Climatological Report (Annual)
Issued by NWS
Issued by NWS
000
CXUS55 KTFX 081402
CLAGTF
CXUS55 KTFX DDHHMM CCA
CLAGTF
MTZ008>015-044>055-081402-
AREA ANNUAL CLIMATE SUMMARY NATIONAL WEATHER SERVICE GREAT FALLS MT
702 AM MST FRI JAN 8 2021
THIS DATA IS PRELIMINARY UNTIL CERTIFIED BY THE NATIONAL CENTERS FOR
ENVIRONMENTAL INFORMATION.
...2020 WEATHER SUMMARY FOR NORTH CENTRAL AND SOUTHWEST MONTANA...
AVERAGE TEMPERATURE / NORMAL/ DEPARTURE FROM NORMAL GREAT
FALLS....45.4 / 44.6... +0.8...60TH WARMEST YEAR OF RECORD.
HAVRE..........44.5 / 43.5... +1.0...33RD WARMEST YEAR OF RECORD.
HELENA.........47.3 / 45.4... +1.9... 6TH WARMEST YEAR OF RECORD.
BOZEMAN........43.9 / 42.8... +1.1...14TH WARMEST YEAR OF RECORD.
CUT BANK.......42.5 / 42.1... +0.4...35TH WARMEST YEAR OF RECORD.
DILLON.........42.8 / 42.8... 0.0...38TH WARMEST YEAR OF RECORD.
LEWISTOWN......43.8 / 43.1... +0.7...40TH WARMEST YEAR OF RECORD.
W YELLOWSTONE..34.8 / 34.4... +0.4...44TH COOLEST YEAR OF RECORD.
HIGHEST / LOWEST TEMPERATURES GREAT FALLS.... 99 ON 08/17 / -18 ON
01/15 HAVRE..........101 ON 08/17 / -28 ON 01/15
HELENA.........100 ON 08/17 / -7 ON 01/15 BOZEMAN........100 ON
09/05 / -20 ON 10/26 CUT BANK....... 97 ON 08/17 / -22 ON 01/15
DILLON......... 95 ON 08/02 / -9 ON 10/26 LEWISTOWN...... 97 ON
09/05 / -16 ON 01/15 W YELLOWSTONE.. 92 ON 08/17 / -33 ON 02/04
THE AREA EXTREMES WERE 102F AT FORT BENTON IN AUGUST AND -36F AT
SIMPSON IN FEBRUARY.
PRECIPITATION / NORMAL / DEPARTURE FROM NORMAL / MOST IN 24 HRS
GREAT FALLS....14.43 / 14.75 / -0.32 / 2.23 ON 06/28-29
HAVRE.......... 9.37 / 11.20 / -1.83 / 0.87 ON 09/06-07
HELENA......... 9.87 / 11.22 / -1.35 / 1.00 ON 10/23-24
BOZEMAN........10.03 / 13.93 / -3.90 / 0.55 ON 06/17-18
CUT BANK.......10.01 / 10.85 / -0.84 / 1.25 ON 05/20-21
DILLON......... 4.53 / 10.50 / -5.97 / 0.59 ON 06/17
LEWISTOWN......14.21 / 16.85 / -2.64 / 1.30 ON 06/28-29 W
YELLOWSTONE..21.51 / 21.32 / +0.19 / 0.91 ON 11/11
THERE WERE SOME EXTENDED DRY PERIODS DURING THE YEAR. THIS TABLE
SUMMARIZES SOME OF THE LONGER PERIODS. THESE PERIODS ARE THROUGH THE
END OF 2020.
NO MORE THAN LOCATION DAYS RECORD
LENGTH
TRACE GREAT FALLS 36 DAYS...LONGEST SINCE 2012 62 DAYS 1907 0.75
HELENA 108 DAYS...LONGEST SINCE 2004 165 DAYS 1930-31 4.00
DILLON 326 DAYS...LONGEST SINCE 1999 332 DAYS 1999-2000 5.00
DILLON 374 DAYS...RECORD OLD RECORD 362 DAYS 1965-66 6.00
DILLON 460 DAYS...RECORD OLD RECORD 408 DAYS 1965-67
SOME TEMPERATURE, PRECIPITATION AND WIND HIGHLIGHTS AND RANKING...
BOZEMAN...THIS WAS THE WARMEST YEAR SINCE 2016. ANNUAL PRECIPITATION
WAS THE 6TH DRIEST OF RECORD AND DRIEST SINCE 2012. THIS
WAS THE 6TH SNOWIEST YEAR OF RECORD.
AVERAGE WIND SPEED OF 5.9-MPH WAS THE HIGHEST SINCE 2014.
CUT BANK..ANNUAL PRECIPITATION WAS THE 39TH DRIEST OF RECORD AND
DRIEST SINCE 2012. THIS WAS THE 5TH SNOWIEST YEAR OF RECORD.
AVERAGE WIND SPEED OF 13.9-MPH WAS THE HIGHEST ANNUAL
AVERAGE SINCE 1999 AND 13TH HIGHEST OF RECORD.
DILLON....ANNUAL PRECIPITATION OF 4.53 WAS THE DRIEST OF RECORD.
THE PREVIOUSLY DRIEST YEAR WAS IN 2012 WHEN 6.19 FELL.
DILLON HAS HAD 374 DAYS WITH NO MORE THAN 5.00-INCHES OF
PRECIPITATION. THIS IS A RECORD. THIS WAS THE 13TH LEAST
SNOWIEST YEAR.
ANNUAL AVERAGE WIND SPEED OF 9.9-MPH WAS THE 13TH HIGHEST
OF RECORD AND HIGHEST SINCE 1990.
GREAT FALLS...THIS WAS THE WAWRMEST YEAR SINCE 2016. THE COLDEST
TEMPERATURE OF -18F WAS THE WARMEST SINCE 2015. THIS WAS THE
15TH SNOWIEST YEAR OF RECORD.
AVERAGE WIND SPEED WAS THE WINDIEST SINCE 1993.
HAVRE.....THIS WAS THE WARMEST YEAR SINCE 2016. ANNUAL PRECIPITATION
WAS THE 29TH DRIEST OF RECORD AND DRIEST SINCE 2017. THIS
WAS THE 25TH SNOWIEST YEAR OF RECORD.
AVERAGE WIND SPEED OF 10.8-MPH WAS THE 6TH HIGHEST OF
RECORD AND HIGHEST SINCE 1978.
HELENA....THIS WAS THE WARMEST YEAR SINCE 2016. THE COLDEST
TEMPERATURE OF -7F WAS THE WARMEST SINCE -6F IN 2015. ANNUAL
PRECIPITATION OF 9.87 WAS THE 34TH DRIEST OF RECORD AND
DRIEST SINCE 2012.
AVERAGE WIND SPEED OF 7.2-MPH WAS THE HIGHEST ANNUAL
AVERAGE SINCE 1999.
LEWISTOWN..THIS WAS THE WARMEST YEAR SINCE 2016. ANNUAL
PRECIPITATION WAS THE 27TH DRIEST OF RECORD AND DRIEST SINCE 2017.
THIS WAS THE 27TH SNOWIEST YEAR OF RECORD.
AVERAGE WIND SPEED OF 9.7-MPH WAS THE HIGHEST SINCE 1999.
SNOWFALL / DEPARTURE FROM NORMAL / MOST IN 24 HRS / MAX SNOW ON GRD
GREAT FALLS.. 82.2 /+19.1 / 12.4 ON 10/17-18 / 10 INCHES ON 10/19
HAVRE.........52.7 /+14.3 / 8.2 ON 03/13-14 / 9 INCHES ON 11/09
HELENA........57.5 /+19.4 / 17.6 ON 10/23-24 / 11 INCHES ON 10/24
BOZEMAN.......75.6 /+35.4 / 7.6 ON 02/05-06 / 9 INCHES ON 04/12
CUT BANK......74.1 /+37.2 / 11.0 ON 03/14 / 5 INCHES ON 10/19*
DILLON........22.1 /-19.3 / 7.2 ON 11/07 / 6 INCHES ON 01/01
LEWISTOWN.... 78.7 /+31.5 / 10.5 ON 11/08 / 14 INCHES ON 11/10
BOZEMAN MSU.. 89.8 / -1.2 / 7.0 ON 10/24 / 12 INCHES ON 02/16* W
YELLOWSTON.132.9 /-27.7 / 8.5 ON 03/15 / 41 INCHES ON 04/04* *
LAST OF MULTIPLE OCCURRENCES
AVERAGE WIND / DEPARTURE FROM NORMAL / PEAK WIND /MPH/ GREAT
FALLS....12.3 MPH / +0.2 / 82 MPH ON 02/01...38TH WINDIEST YR
HAVRE..........10.8 MPH / +1.7 / 63 MPH ON 10/30... 6TH WINDIEST YR
HELENA......... 7.2 MPH / +0.2 / 59 MPH ON 06/13...42ND WINDIEST YR
BOZEMAN........ 5.9 MPH / +0.3 / 57 MPH ON 06/06...30TH WINDIEST YR
CUT BANK.......13.9 MPH / +1.3 / 78 MPH ON 02/01...12TH WINDIEST YR
DILLON......... 9.9 MPH / +0.9 / 60 MPH ON 05/06...13TH WINDIEST YR
LEWISTOWN...... 9.7 MPH / +0.4 / 69 MPH ON 12/20...27TH WINDIEST YR
W YELLOWSTONE.. 55 MPH ON 05/03
THE PERSISTENT WINDY CONDITIONS DURING THE YEAR PRODUCED SOME
NOTABLE NUMBERS. SEE THE TABLES BELOW FOR DAYS OF GUSTS GREATER THAN
45 MPH AND 55 MPH, AND DAYS WITH WIND AVERAGES GREATER THAN 20 MPH
AND GREATER THAN 25 MPH.
JANUARY THROUGH DECEMBER... DAYS OF
GUSTS... >44 MPH MOST SINCE >54 MPH MOST SINCE
BOZEMAN 20* 18 IN 2012 2 2 IN 2017 CUT BANK 84
86 IN 2011 27 30 IN 2007 GREAT FALLS 62 70 IN 1990
18 22 IN 1990 HAVRE 29 35 IN 2012 2 3
IN 2015 HELENA 30 31 IN 2011 4 8 IN 2014
* AT BOZEMAN A RECORD 20-DAYS WITH GUSTS OF 45-MPH OR GREATER FOR
THE YEAR. THIS EXCEEDS THE OLD RECORD OF 18-DAYS LAST SET IN 2012.
DAYS OF WIND SPEED AVERAGES... >20
MPH MOST SINCE AVG >25 MPH MOST SINCE CUT BANK 68
79 IN 1999 50 28 30 IN 1997 GREAT FALLS 33 35 IN
2007 26 6 7 IN 2017 HAVRE 14 16 IN 2002
8 1 2 IN 2019
LAST SPRING FROST / FIRST FALL FROST GROWING SEASON
AVERAGE AVERAGE DAYS NORMAL GREAT
FALLS....05/23 05/20 / 09/08 09/21 107 123
HAVRE..........05/14 05/15 / 10/01 09/21 139 128
HELENA.........05/05 05/15 / 10/17 09/24 164 130
BOZEMAN........05/11 06/02 / 09/08 09/11 119 101 CUT
BANK.......05/13 05/24 / 09/08 09/11 117 109
DILLON.........06/15 06/08 / 09/08 09/13 84 102
LEWISTOWN......05/14 05/26 / 09/08 09/17 116 113 W
YELLOWSTONE..07/16 06/24 / 08/15 07/13 29 15
BOZEMANS LAST SPRING FREEZING TEMPERATURE ON MAY 11 WAS THEIR
EARLIEST SINCE 2015 AND FOURTH EARLIEST OF RECORD. THE EARLIEST WAS
ON MAY 4, 1972.
DILLON HAD THEIR SHORTEST FREEZE-FREE PERIOD SINCE 2007 AND 10TH
SHORTEST OF RECORD.
GREAT FALLS HAD THEIR SHORTEST FROST-FREE SEASON SINCE 2009. THEIR
FIRST FALL FREEZING TEMPERATURE ON SEPTEMBER 8 WAS THE EARLIEST
SINCE 2002 AND SIXTH EARLIEST OF RECORD.
HELENA HAD THEIR LONGEST FREEZE-FREE PERIOD OF 164-DAYS SINCE 1881,
AND SECOND LONGEST OF RECORD.
DAYS OF MAXIMUM TEMPERATURE 90F OR HIGHER / 32F OR LOWER 80F OR
HIGHER AT WEST YELLOWSTONE AVERAGE AVERAGE
GREAT FALLS.... 21 18 / 39 40 HAVRE.......... 31 24 /
55 54 HELENA......... 31 24 / 25 41 BOZEMAN........ 20
22 / 39 45 CUT BANK....... 14 8 / 53 48
DILLON......... 10 8 / 53 45 LEWISTOWN...... 10 11 /
44 44 W YELLOWSTONE.. 45 40 / 98 91
DAYS WITH MINIMUM TEMPERATURE 32F OR LOWER / 0F OR LOWER
AVERAGE AVERAGE GREAT FALLS.... 176 166 / 13 21
HAVRE.......... 189 180 / 21 31 HELENA......... 172 167 /
7 18 BOZEMAN........ 198 178 / 10 22 CUT BANK....... 185
183 / 17 27 DILLON......... 201 191 / 5 14
LEWISTOWN...... 192 181 / 15 21 W YELLOWSTONE.. 240 256 /
66 55
DAYS WITH PRECIPITATION MORE THAN TR =>0.01 NML
=>0.10 NML =>0.50 NML SNOW NML GREAT FALLS.... 80 99 35
40 6 4 44 69 HAVRE.......... 89 84 28 33
1 4 31 55 HELENA......... 78 88 27 33 6 4
28 62 BOZEMAN........ 92 102 31 44 3 4 46
66 CUT BANK....... 83 77 25 26 4 4 DILLON.........
44 80 16 29 1 4 LEWISTOWN...... 108 113 47 47
9 4 41 49
MONTHLY AVERAGE TEMPERATURE JAN FEB MAR
APR MAY JUN JUL AUG SEP OCT NOV DEC BZN 29.2 23.4 33.1 41.0
52.5 58.7 65.9 67.3 57.2 40.4 31.7 26.9 CTB 21.2 27.3 27.6 37.1
50.0 58.3 64.0 66.2 56.5 37.1 34.8 29.8 DLN 25.1 24.2 31.3 40.0
50.2 56.6 64.1 66.4 56.8 42.0 31.5 25.6 GTF 26.7 30.0 31.7 39.2
51.3 60.2 66.5 68.9 58.9 40.8 37.2 33.8 HVR 20.2 28.1 29.5 39.3
53.8 63.4 68.8 70.3 58.6 39.2 32.7 30.4 HLN 29.4 31.8 34.6 43.8
54.5 61.8 69.5 71.9 61.3 43.2 35.6 30.7 LWT 26.5 25.9 30.7 37.1
50.1 58.3 65.2 67.6 57.8 39.7 35.5 30.7 WYS 18.7 10.5 25.7 30.9
44.7 50.3 57.1 59.1 49.7 34.8 21.8 13.5
MONTHLY PRECIPITATION JAN FEB MAR
APR MAY JUN JUL AUG SEP OCT NOV DEC BZN 0.19 0.76 1.18 0.74
0.85 3.30 0.93 0.20 0.44 1.11 0.27 0.06 CTB 0.06 0.25 0.73 0.39
1.92 2.65 0.10 0.24 0.65 1.47 1.12 0.25 DLN 0.01 0.29 0.23 0.15
0.38 2.29 0.18 0.34 0.40 0.04 0.21 0.01 GTF 0.07 0.41 0.89 0.73
3.34 4.73 0.60 0.10 0.49 2.04 0.93 0.10 HVR 0.36 0.31 0.63 0.42
1.30 2.64 0.49 0.03 1.62 0.84 0.65 0.08 HLN 0.10 0.20 0.95 0.72
1.57 3.15 0.26 0.07 0.25 2.03 0.36 0.21 LWT 0.42 0.79 0.41 0.91
3.76 3.64 0.46 1.14 0.63 1.32 0.35 0.38 WYS 2.39 1.64 2.24 0.90
2.85 2.86 1.18 0.67 0.47 1.72 2.20 2.06
MONTHLY SNOWFALL JAN FEB MAR APR
MAY JUN JUL AUG SEP OCT NOV DEC BZN 1.6 2.2 10.8 10.2 T
0 0 0 0 10.0 9.2 2.8 MSU 6.0 29.7 14.9 10.4 0.3 0
0 0 T 17.8 6.4 8.3 CTB 2.9 11.3 11.8 9.0 0 0 0
0 0 20.9 13.6 4.6 DLN 0.2 6.7 4.2 0.2 0 0 0 0
T 0.5 7.4 2.9 GTF 1.3 6.3 21.3 8.5 1.5 0 0 0 0
28.0 14.2 1.1 HVR 3.2 3.9 14.7 8.7 0 0 0 0 0 8.9
10.1 0.7 HLN 0.6 2.8 13.4 3.5 T 0 0 0 0 25.4
3.9 2.7 LWT 1.9 4.9 8.7 5.3 11.0 0 0 0 T 10.5 15.3
4.7 WYS 33.6 20.0 19.1 6.0 0.5 T 0 0 T 6.3 20.3 18.4
DAYS WITH... ANY FOG FOG VSBY <1/4SM GLAZE THUNDER
2020 AVG 2020 AVG 2020 AVG 2020 AVG BZN 98
106 14 18 0 1 25 31 CTB 106 104 27
25 0 0 11 16 DLN 66 75 8 10 0 0
19 32 GTF 82 95 19 20 1 2 20 19
HVR 93 97 14 18 1 2 15 29 HLN 44
79 5 14 1 1 23 25 LWT 94 107 15
20 4 1 25 28
MILESTONES REACHED DURING 2020... BOZEMAN...
JAN...AVERAGE TEMPERATURE OF 29.2F WAS THE THIRD WARMEST OF RECORD,
AND THE WARMEST SINCE 1994. AVERAGE IS 21.1F.
FEB...SNOWFALL OF 20.4 WAS THE SECOND HIGHEST OF RECORD AND HIGHEST
SINCE 2019. AVERAGE IS 4.9.
MAR...SNOWFALL OF 18.1 WAS THE SIXTH HIGHEST OF RECORD AND HIGHEST
SINCE 1995. AVERAGE IS 7.7.
APR...SNOWFALL OF 10.2 WAS THE EIGHTH HIGHEST OF RECORD AND HIGHEST
SINCE 1995. AVERAGE IS 7.5.
MONTHLY PEAK GUST OF 38-MPH WAS THE LOWEST APRIL MONTHLY
SINCE 2003.
MAY...PRECIPITATION OF 0.85-INCHES WAS THE THIRD DRIEST OF RECORD
AND DRIEST SINCE 1973. AVERAGE IS 2.38-INCHES.
AUG...PRECIPITATION OF 0.20-INCHES WAS THE FIFTH DRIEST OF RECORD
AND DRIEST SINCE 2017. AVERAGE IS 1.07-INCHES.
OCT...SNOWFALL OF 10.0 WAS THE SECOND HIGHEST OF RECORD AND HIGHEST
SINCE 1969. AVERAGE IS 2.1.
NOV...PRECIPITATION OF 0.27-INCHES WAS THE EIGHTH DRIEST OF RECORD
AND DRIEST SINCE 2006. AVERAGE IS 0.75-INCHES.
SPRING (MAR-MAY)...PRECIPITATION OF 2.77-INCHES WAS THE FIFTH
DRIEST OF RECORD AND DRIEST SINCE 2001. AVERAGE IS 4.86.
SNOWFALL OF 28.3 WAS THE FIFTH HIGHEST OF RECORD AND HIGHEST
SINCE 1995. AVERAGE IS 17.7.
FALL (SEP-NOV)...PRECIPITATION OF 1.82-INCHES WAS THE NINTH DRIEST
OF RECORD AND DRIEST SINCE 2012. AVERAGE IS 2.93.
SNOWFALL OF 19.2 WAS THE FOURTH HIGHEST OF RECORD AND HIGHEST
SINCE 1975. AVERAGE IS 7.6.
WATER YEAR ENDING SEP...SNOWFALL OF 68.4 WAS THE SIXTH HIGHEST OF
RECORD AND HIGHEST SINCE 2018. AVERAGE IS 40.2.
CUT BANK...
FEB...SNOWFALL OF 11.3 WAS THE TENTH HIGHEST OF RECORD AND HIGHEST
SINCE 2019. AVERAGE IS 4.8.
AVERAGE WIND SPEED OF 17.0-MPH WAS THE TENTH HIGHEST OF
RECORD AND HIGHEST SINCE 1999. AVERAGE IS 12.8-MPH.
AVERAGE WIND SPEED OF 36.4-MPH ON THE 1ST IS THE FIFTH
HIGHEST OF RECORD FOR FEBRUARY AND THE HIGHEST IN FEBRUARY SINCE
1950. THIS IS HIGHEST AVERAGE DAILY WIND SPEED SINCE MARCH 2010.
MAR...SNOWFALL OF 11.8 WAS THE TENTH HIGHEST OF RECORD AND HIGHEST
SINCE 2005. AVERAGE IS 7.4.
PEAK WIND GUST OF 71-MPH ON THE 4TH WAS THE FOURTH HIGHEST
OF RECORD FOR MARCH AND HIGHEST IN MARCH SINCE 1967.
RECORD IS 78-MPH SET IN 1961.
MAY...PEAK WIND GUST OF 65-MPH ON THE 31ST WAS THE FOURTH HIGHEST
OF RECORD FOR MAY AND HIGHEST IN MAY SINCE 1999.
RECORD IS 72-MPH SET IN 1986.
JUL...PRECIPITATION OF 0.10-INCHES WAS THE TENTH DRIEST OF RECORD
AND DRIEST SINCE 2017. AVERAGE IS 1.28-INCHES.
OCT...PRECIPITATION OF 1.47-INCHES WAS THE SIXTH WETTEST OF RECORD
AND WETTEST SINCE 2011. AVERAGE IS 0.44.
SNOWFALL OF 20.9 WAS THE HIGHEST OF RECORD, EXCEEDING THE
PREVIOUS RECORD OF 17.5 SET IN 1934. AVERAGE IS 2.5.
HIGHEST SINCE 2005. AVERAGE IS 7.4.
NOV...PRECIPITATION OF 1.00-INCH WAS THE NINTH WETTEST OF RECORD
AND WETTEST SINCE 2015. AVERAGE IS 0.36.
SNOWFALL OF 11.8 WAS THE TENTH HIGHEST OF RECORD AND HIGHEST
SINCE 2019. AVERAGE IS 5.0.
AVERAGE WIND SPEED OF 18.4-MPH WAS THE SIXTH HIGHEST OF
RECORD AND HIGHEST SINCE 1989. AVERAGE IS 14.3-MPH.
SPRING (MAR-MAY)...SNOWFALL OF 20.8 WAS THE TENTH HIGHEST OF RECORD
AND HIGHEST SINCE 2018. AVERAGE IS 13.4.
FALL (SEP-NOV)...SNOWFALL OF 34.5 WAS THE THIRD HIGHEST OF RECORD
AND HIGHEST SINCE 2019. AVERAGE IS 7.8.
AVERAGE WIND SPEED OF 14.6-MPH WAS THE SEVENTH HIGHEST OF
RECORD AND HIGHEST SINCE 1990. AVERAGE IS 12.8-MPH.
WATER YEAR ENDING SEP...SNOWFALL OF 78.9 WAS THE SIXTH HIGHEST OF
RECORD AND HIGHEST SINCE 2019. AVERAGE IS 36.9.
DILLON...
JAN...PRECIPITATION OF 0.01 WAS THE FOURTH DRIEST OF RECORD AND
DRIEST SINCE 2015. AVERAGE IS 0.26.
APR...PRECIPITATION OF 0.23 WAS THE THIRD DRIEST OF RECORD AND
DRIEST SINCE 2013. AVERAGE IS 1.07.
MAY...PRECIPITATION OF 0.15 WAS THE THIRD DRIEST OF RECORD AND
DRIEST SINCE 2001. AVERAGE IS 1.93.
PEAK WIND GUST OF 60-MPH ON THE 6TH WAS THE FIFTH HIGHEST
OF RECORD FOR MAY AND HIGHEST IN MAY SINCE 2008.
RECORD IS 65-MPH SET IN 1981.
JUL...PRECIPITATION OF 0.18 WAS THE SIXTH DRIEST OF RECORD AND
DRIEST SINCE 2018. AVERAGE IS 1.25.
OCT...PRECIPITATION OF 0.04 WAS THE FIFTH DRIEST OF RECORD AND
DRIEST SINCE 2002. AVERAGE IS 0.69.
AVERAGE WIND SPEED OF 10.7-MPH WAS THE SEVENTH HIGHEST OF
RECORD AND HIGHEST SINCE 1990. AVERAGE IS 8.8-MPH.
SPRING (MAR-MAY)...PRECIPITATION OF 0.76-INCHES WAS THE DRIEST OF
RECORD. PREVIOUS RECORD WAS 1.15 IN 1966. AVERAGE IS 3.54.
FALL (SEP-NOV)...PRECIPITATION OF 0.65-INCHES WAS THE FOURTH DRIEST
OF RECORD AND DRIEST SINCE 2003. AVERAGE IS 1.92.
WATER YEAR ENDING SEP...PRECIPITATION OF 5.49-INCHES WAS THE DRIEST
OF RECORD, EDGING 1979 WITH 5.73. AVERAGE IS 10.50-INCHES.
GREAT FALLS...
JAN...SNOWFALL OF 1.3 WAS THE TENTH LOWEST OF RECORD AND LEAST
SINCE 1995. AVERAGE IS 8.5.
FEB...PEAK GUST OF 82-MPH ON THE FIRST WAS THE SECOND HIGHEST
FEBRUARY GUST OF RECORD AND HIGHEST SINCE 87-MPH SET IN 1972.
THIS WAS THE HIGHEST GUST AT GREAT FALLS SINCE AUGUST 2003.
AVERAGE WIND SPEED OF 33.4-MPH ON THE 1ST IS THE FOURTH
HIGHEST OF RECORD FOR FEBRUARY AND THE HIGHEST IN FEBRUARY SINCE
1989. THIS IS HIGHEST AVERAGE DAILY WIND SPEED SINCE DECEMBER 1990.
MAR...SNOWFALL OF 21.3 WAS THE EIGHTH HIGHEST OF RECORD AND HIGHEST
SINCE 2005. AVERAGE IS 11.9.
AUG...PRECIPITATION OF 0.10 WAS THE FIFTH DRIEST OF RECORD AND
DRIEST SINCE 2017. AVERAGE IS 1.57.
OCT...SNOWFALL OF 28.0 WAS THE HIGHEST OF RECORD EXCEEDING THE
PREVIOUS RECORD OF 18.5 SET IN 1925. AVERAGE IS 4.1. THIS WAS
THE 7TH HIGHEST AMOUNT FOR ANY MONTH.
PEAK GUST OF 66-MPH WAS THE HIGHEST OCTOBER GUST SINCE 1991.
24-HOUR SNOWFALL OF 12.4 WAS THE HIGHEST OF RECORD FOR SUCH
A PERIOD. THE PREVIOUS HIGH WAS 8.3 IN 1957.
NOV...AVERAGE WIND SPEED OF 16.8-MPH WAS THE SEVENTHHIGHEST OF
RECORD AND HIGHEST SINCE 1990. AVERAGE IS 14.2-MPH.
LOW TEMP OF 54F ON 4TH WAS THE SECOND WARMEST NOVEMBER
MINIMUM OF RECORD. THE WARMEST MINIMUM FOR DECEMBER WAS 55F ON
DEC 7, 2006.
DEC...LOW TEMP OF 51F ON 8TH WAS THE SECOND WARMEST DECEMBER
MINIMUM OF RECORD. THE WARMEST MINIMUM FOR DECEMBER WAS 53F ON
DEC 16, 1980.
WINTER (DEC-FEB)...PRECIPITATION OF 0.65-INCHES WAS THE EIGHTH
DRIEST OF RECORD AND DRIEST SINCE 2005. AVERAGE IS 1.53.
FALL (SEP-NOV)...SNOWFALL OF 42.2-INCHES WAS THE SECOND HIGHEST
OF RECORD AND MOST SINCE 2019. AVERAGE IS 13.4.
WATER YEAR ENDING SEP...SNOWFALL OF 95.6 WAS THE SEVENTH HIGHEST
OF RECORD AND HIGHEST SINCE 2019. AVERAGE IS 63.1.
HAVRE...
FEB...AVERAGE WIND SPEED OF 11.8-MPH WAS THE TENTH HIGHEST OF
RECORD AND HIGHEST SINCE 2011. AVERAGE IS 8.9-MPH.
MAR...SNOWFALL OF 14.7 WAS THE TENTH HIGHEST OF RECORD AND HIGHEST
SINCE 1996. AVERAGE IS 6.3.
APR...SNOWFALL OF 11.2 WAS THE EIGHTH HIGHEST OF RECORD AND HIGHEST
SINCE 1975. AVERAGE IS 3.0.
JUN...AVERAGE WIND SPEED OF 11.0-MPH WAS THE EIGHTH HIGHEST OF
RECORD AND HIGHEST SINCE 2012. AVERAGE IS 9.0-MPH.
JUL...MONTHLY PEAK GUST OF 41-MPH WAS THE LOWEST JULY MONTHLY
SINCE 1997.
AUG...PRECIPITATION OF 0.03 WAS THE THIRD DRIEST OF RECORD AND
DRIEST SINCE 1969. AVERAGE IS 1.11.
OCT...SNOWFALL OF 8.9 WAS THE EIGHTH HIGHEST OF RECORD AND HIGHEST
SINCE 1991. AVERAGE IS 2.0.
MONTHLY PEAK GUST OF 63-MPH ON THE 30TH TIED FOR THE SECOND
HIGHEST OCTOBER GUST OF RECORD. HIGHEST IS 69-MPH SET IN 1999.
NOV...AVERAGE WIND SPEED OF 13.2-MPH WAS THE SECOND HIGHEST OF
RECORD AND HIGHEST SINCE 1890. AVERAGE IS 9.3-MPH.
SPRING (MAR-MAY)...SNOWFALL OF 25.9 WAS THE SEVENTH HIGHEST OF
RECORD AND HIGHEST SINCE 1982. AVERAGE IS 11.0.
FALL (SEP-NOV)...SNOWFALL OF 19.0-INCHES WAS THE SIXTH HIGHEST OF
RECORD AND MOST SINCE 2019. AVERAGE IS 7.6.
AVERAGE WIND SPEED OF 11.1-MPH WAS THE SIXTH HIGHEST OF
RECORD AND HIGHEST SINCE 1978. AVERAGE IS 8.9-MPH.
WATER YEAR ENDING SEP...SNOWFALL OF 66.7 WAS THE NINTH HIGHEST OF
RECORD AND HIGHEST SINCE 2018. AVERAGE IS 38.4.
AVERAGE WIND SPEED OF 10.7-MPH WAS THE EIGHTH HIGHEST OF
RECORD AND HIGHEST SINCE 2002. AVERAGE IS 9.1-MPH.
HELENA... JAN...PRECIPITATION OF 0.10 WAS THE SEVENTH DRIEST OF
RECORD AND DRIEST SINCE 2007. AVERAGE IS 0.36.
SNOWFALL OF 0.6 WAS THE FIFTH LOWEST OF RECORD AND LOWEST
SINCE 1995. AVERAGE IS 6.2.
AUG...AVERAGE TEMPERATURE OF 71.9F WAS THE FIFTH WARMEST OF RECORD,
AND THE WARMEST SINCE 2003. AVERAGE IS 68.3F.
PRECIPITATION OF 0.07 WAS THE SIXTH DRIEST OF RECORD AND
DRIEST SINCE 2017. AVERAGE IS 1.20.
OCT...SNOWFALL OF 25.4 WAS THE SECOND HIGHEST OF RECORD AND MOST
SINCE 27.7 IN 1925. AVERAGE IS 2.5.
WINTER (DEC-FEB)...AVERAGE TEMPERATURE OF 30.4F WAS THE FIFTH
WARMEST OF RECORD AND THE WARMEST SINCE 1934. AVERAGE IS 24.2F.
SNOWFALL OF 4.2 WAS THE THIRD LOWEST OF RECORD AND LOWEST
SINCE 1995. AVERAGE IS 18.5.
FALL (SEP-NOV)...SNOWFALL OF 29.3-INCHES WAS THE SIXTH HIGHEST OF
RECORD AND MOST SINCE 1925. AVERAGE IS 8.5.
LEWISTOWN... MAR...A PEAK WIND GUST OF 64-MPH ON THE 4TH WAS THE
SECOND HIGHEST MARCH GUST OF RECORD. THE HIGHEST IS 68-MPH SET
IN 1974.
APR...MONTHLY PEAK GUST OF 41-MPH WAS THE LOWEST APRIL MONTHLY
SINCE 1999.
MAY...SNOWFALL OF 11.0 WAS THE SIXTH HIGHEST OF RECORD AND MOST
SINCE 1983. AVERAGE IS 0.8.
JUL...PRECIPITATION OF 0.46 WAS THE TENTH DRIEST OF RECORD AND
DRIEST SINCE 2017. AVERAGE IS 1.93.
NOV...AVERAGE WIND SPEED OF 12.5-MPH WAS THE NINTH HIGHEST OF
RECORD AND HIGHEST SINCE 2006. AVERAGE IS 10.1-MPH.
FALL (SEP-NOV)...SNOWFALL OF 25.8-INCHES WAS THE SEVENTH HIGHEST
OF RECORD AND MOST SINCE 1975. AVERAGE IS 8.2.
WEST YELLOWSTONE... JAN...AVERAGE TEMPERATURE OF 18.7F WAS THE
SEVENTH WARMEST OF RECORD AND WARMEST SINCE 2003. AVERAGE IS
12.5F.
NEW RECORD TEMPERATURE WARM|
DAILY WIND DAILY HIGHS LOWS LOWS| HIGH AVG
LOW AVG GUST PRECIP BOZEMAN 1 10 3 8 4 15
5 CUT BANK 1 7 2 8 4 12 1
DILLON 0 9 1 2 3 18 8 GREAT
FALLS 1 9 2 3 3 10 4 HAVRE 1
7 0 9 1 14 3 HELENA 0 3 0
4 5 15 3 LEWISTOWN 0 6 1 4 0
11 2 W YELLOWSTONE 0 0 0 0
FOLLOWING IS A MONTHLY LISTING OF THE EXTREMES RECORDED AND
LOCATIONS.
TEMPERATURE
JANUARY...HIGH TEMP........FORT BENTON............59F ON THE 24TH
LOW TEMP.........SIMPSON...............-36F ON THE 15TH HIGHEST
PRECIP...WEST YELLOWSTONE.......1.95 INCHES BLACK BEAR
SNOTEL......6.10 INCHES HIGH WIND GUST...DEEP CREEK
RAWS........97 MPH ON THE 31ST BABB...................91 MPH
ON THE 31ST
FEBRUARY..HIGH TEMP........FORT BENTON............68F ON THE 1ST
ARMELLS CREEK..........68F ON THE 1ST LOW
TEMP.........WEST YELLOWSTONE......-33F ON THE 4TH HIGHEST
PRECIP...BOZEMAN 4S.............2.97 INCHES SHOWER FALLS
SNOTEL....7.30 INCHES HIGH WIND GUST...DEEP CREEK
RAWS.......106 MPH ON THE 1ST BROWNING...............89 MPH ON
THE 1ST
##### MARCH.....HIGH TEMP........FORT BENTON............72F ON THE
6TH LOMA...................72F ON THE 6TH
LOW TEMP.........NEVADA RIDGE SNOTEL...-15F ON THE 15TH
BADGER PASS SNOTEL....-15F ON THE 15TH HIGHEST
PRECIP...WEST YELLOWSTONE.......2.16 INCHES BLACK BEAR
SNOTEL......7.00 INCHES HIGH WIND GUST...DEEP CREEK
RAWS........87 MPH ON THE 1ST BROWNING...............76 MPH ON
THE 2ND
APRIL.....HIGH TEMP........HELENA.................83F ON THE 29TH
LOW TEMP.........ROCKY BOY.............-14F ON THE 2ND HIGHEST
PRECIP...EAST GLACIER...........2.52 INCHES BADGER PASS
SNOTEL.....4.50 INCHES HIGH WIND GUST...DEEP CREEK
RAWS........72 MPH ON THE 1ST FORT BENTON............62 MPH ON
THE 7TH BROWNING...............62 MPH ON THE 27TH
##### MAY.......HIGH TEMP........HAVRE..................90F ON THE
31ST ENNIS..................90F ON THE
30TH LOW TEMP.........YELLOW MULE RAWS.......16F ON THE 7TH
HIGHEST PRECIP...NEAR LEWISTOWN.........4.05 INCHES
CRYSTAL LAKE SNOTEL....6.90 INCHES HIGH WIND
GUST...JUDITH PEAK RAWS.......73 MPH ON THE 18TH
JUNE......HIGH TEMP........ARMELLS CREEK..........93F ON THE 13TH
HAVRE..................93F ON 13TH/24TH
VALENTINE..............93F ON THE 13TH LOW
TEMP.........YELLOW MULE RAWS.......21F ON THE 8TH HIGHEST
PRECIP...HOLTER DAM.............5.73 INCHES DARKHORSE LAKE
SNOTEL..9.40 INCHES HIGH WIND GUST...DEEP CREEK
RAWS........77 MPH ON THE 13TH TWIN BRIDGES...........74 MPH
ON THE 24TH
##### JULY......HIGH TEMP........ARMELLS CREEK.........101F ON THE
22ND LOW TEMP.........WISDOM.................25F ON THE
17TH HIGHEST PRECIP...NEAR BOZEMAN...........1.67 INCHES
HIGH WIND GUST...ROY....................75 MPH ON THE 7TH
AUGUST....HIGH TEMP........FORT BENTON...........102F ON THE 17ND
LITTLE BULLWHACKER....102F ON THE 17TH LOW
TEMP.........ELK PARK...............22F ON THE 14TH HIGHEST
PRECIP...ENNIS..................2.25 INCHES WHISKEY CREEK
SNOTEL...3.50 INCHES HIGH WIND GUST...TWIN
BRIDGES...........71 MPH ON THE 26TH
##### SEPTEMBER.HIGH TEMP........BOZEMAN...............100F ON THE
5TH LOMA..................100F ON THE 5TH
LOW TEMP.........YELLOW MULE RAWS.......14F ON THE 8TH
HIGHEST PRECIP...ROCKY BOY..............3.20 INCHES
WHISKEY CREEK SNOTEL...3.50 INCHES HIGH WIND
GUST...BROWNING...............70 MPH ON THE 24TH DEEP
CREEK RAWS........70 MPH ON THE 25TH
OCTOBER...HIGH TEMP........ARMELLS CREEK..........88F ON THE 10TH
LOW TEMP.........RINGLING..............-29F ON THE 26TH HIGHEST
PRECIP...ST MARY................3.42 INCHES COPPER CAMP
SNOTEL.....8.40 INCHES HIGH WIND GUST...DEEP CREEK
RAWS........85 MPH ON THE 27TH YELLOW MULE RAWS.......82 MPH
ON THE 11TH
##### NOVEMBER..HIGH TEMP........ARMELLS CREEK..........81F ON THE
2ND LOW TEMP.........WEST YELLOWSTONE.......-19F ON THE
29TH HIGHEST PRECIP...EAST GLACIER...........3.69 INCHES
BADGER CREEK SNOTEL....3.50 INCHES HIGH WIND
GUST...DEEP CREEK RAWS........92 MPH ON THE 27TH
AUGUSTA, BROWNING......75 MPH ON THE 5TH
DECEMBER..HIGH TEMP........ARMELLS CREEK..........68F ON THE 8TH
LOW TEMP.........WEST YELLOWSTONE.......-26F ON THE 29TH
HIGHEST PRECIP...CHINOOK 11S............1.95 INCHES PIKE
CREEK SNOTEL......4.20 INCHES HIGH WIND GUST...DEEP CREEK
RAWS........96 MPH ON THE 20TH BYNUM 14W..............81 MPH
ON THE 19TH
#####
FOLLOWING IS A MONTHLY SUMMARY OF WEATHER CONDITIONS OBSERVED.
JANUARY...
A WEAK RIDGE OF HIGH PRESSURE WAS OVER WESTERN NORTH AMERICA DURING
JANUARY, BRINGING WESTERLY FLOW. NORMALLY, FLOW IS FROM THE
NORTHWEST, BUT THIS WESTERLY FLOW BROUGHT GENERALLY ABOVE NORMAL
AVERAGE TEMPERATURES, EXCEPT OVER NORTH CENTRAL MONTANA. IT ALSO
BROUGHT ABOVE NORMAL PRECIPITATION OVER WESTERN MONTANA, BUT VERY
DRY CONDITIONS ACROSS EASTERN MONTANA. THE FIRST WEEK OF THE MONTH
WAS MILD, WITH SOME HEAVY SNOW OVER THE WESTERN PORTIONS ON THE 1ST.
GUSTY WINDS PREVAILED ON THE 4TH, WITH GUSTS OF 76 MPH AT CUT BANK
AND 74 MPH AT FORT BELKNAP.
THE 7TH ALSO BROUGHT GUSTY WINDS, WITH SPEEDS REACHING 73 MPH NEAR
PENDROY AND 73 MPH WEST OF BYNUM. HEAVY SNOW FELL AT LINCOLN (10-
INCHES) AND KINGS HILL (12-INCHES). COLDER AIR SETTLED ACROSS THE
AREA BY THE 9TH. SIMPSON RECORDED THE LOWEST TEMPERATURE IN THE
STATE ON THE 15TH (-36F). WINDS PICKED UP AS WARMER AIR MOVED IN ON
THE 18TH. WIND CHILLS AS LOW AS -41F WERE FELT AT HAVRE AND SWEET
GRASS. FOR THE REST OF THE MONTH, MILD CONDITIONS PREVAILED. THIS
ALSO BROUGHT A WINDIER PERIOD AS WELL. THE WARMEST DAY WAS THE 24TH,
WHEN FORT BENTON REACHED 59F. STRONG WINDS BEGAN ON THE 31ST AND
CONTINUED ON FEBRUARY 1ST. ON THE 31ST, GUSTS REACHED 97 MPH AT DEEP
CREEK RAWS AND 91 MPH AT BABB. EVEN STRONGER GUSTS OF 106 MPH
OCCURRED AT DEEP CREEK RAWS ON FEBRUARY 1ST. WIDESPREAD GUSTS OVER
80 MPH WERE MEASURED OVER PORTIONS OF THE ROCKY MOUNTAIN FRONT,
INCLUDING GREAT FALLS.
WEST YELLOWSTONE RECORDED THEIR WARMEST JANUARY SINCE 2003, WHILE
HELENA HAD THEIR WARMEST SINCE 2007. BOZEMAN HAD THEIR THIRD WARMEST
OF RECORD, AND WARMEST SINCE 1994.
DILLON HAD THEIR 4TH DRIEST JANUARY OF RECORD AND DRIEST SINCE 2015.
HELENA HAD THEIR DRIEST JANUARY SINCE 2007, AND 5TH LOWEST JANUARY
SNOWFALL. AS A WHOLE, THE AREA HAD THEIR DRIEST JANUARY SINCE 2009.
THE EXTENDED DRYNESS, WHICH STARTED AROUND DECEMBER 1, 2019,
RESULTED IN A 68-DAY STRETCH DURING WHICH NO MORE THAN 0.15 HAS
FALLEN AT HELENA FOR A 66-DAY PERIOD. THIS IS THEIR 7TH LONGEST
PERIOD FOR THIS ELEMENT...THROUGH THE END OF JANUARY.
########
FEBRUARY...
ABOVE NORMAL TEMPERATURES DOMINATED NORTHERN PORTIONS OF THE AREA,
WHILE TEMPERATURES AVERAGED BELOW NORMAL OVER THE SOUTHWEST. A BROAD
RIDGE OF HIGH PRESSURE WAS OVER WESTERN NORTH AMERICA, WHICH IS
NORMAL FOR FEBRUARY. PRECIPITATION WAS BELOW NORMAL MOST AREAS WITH
ABOVE NORMAL TEMPERATURES, AND ABOVE NORMAL OVER PORTIONS OF THE
SOUTHWEST. BOZEMAN MSU HAD THEIR SNOWIEST FEBRUARY OF RECORD,
EXCEEDING LAST YEARS TOTAL BY ONE-HALF INCH. WINDS AVERAGED ABOVE
NORMAL MOST AREAS.
AFTER A WARM START, WITH TEMPERATURES IN THE 60S ACROSS NORTH
CENTRAL MONTANA, TEMPERATURES DROPPED TO NEAR AND BELOW ZERO BY THE
3RD. THE LOWEST TEMPERATURE IN THE STATE OCCURRED ON THE 4TH, WHEN
WEST YELLOWSTONE DROPPED TO -33F. WARMER CONDITIONS RETURNED, WITH
SOME SNOW FROM THE 4TH THROUGH 12TH. COLDER AIR AGAIN MOVED IN FROM
THE 17TH THROUGH 20TH, WITH A -31F VALUE RECORDED AT WEST
YELLOWSTONE ON THE 20TH. AFTER A BRIEF WARMING, SNOW FELL MOST AREAS
ON THE 24TH. THE MONTH ROUNDED OUT WITH TEMPERATURES IN THE UPPER
50S OVER NORTH CENTRAL MONTANA ON THE 28TH.
WIND SPEEDS AVERAGED ABOVE NORMAL. CUT BANKS AVERAGE OF 17.0 MPH
WAS THEIR WINDIEST SINCE 2002. HELENA HAD THEIR WINDIEST FEBRUARY
SINCE 1999. THE HIGHEST WIND GUST WAS 106 MPH AT DEEP CREEK RAWS.
THIS WAS THE STRONGEST GUST IN MONTANA SINCE A THUNDERSTORM GUST OF
115 MPH IN JUNE 2017 AND AN ALL-TIME FEBRUARY AT DEEP CREEK.
THE PEAK GUST OF 82 MPH AT GREAT FALLS ON THE 1ST WAS THE SECOND
HIGHEST FEBRUARY GUST OF RECORD. IT TIED AS THE SEVENTH HIGHEST GUST
OF RECORD AT GREAT FALLS AND WAS THE HIGHEST GUST SINCE A
THUNDERSTORM GUST OF 83 MPH ON AUGUST 8 2003.
*** 2019-20 WINTER SEASON SNOWFALL AND EXTENDED DRYNESS ***
THROUGH THE END OF FEBRUARY, CUT BANK RECEIVED 78.5-INCHES OF SNOW
FOR THE SEASON, SETTING A NEW SEASONAL RECORD. THEIR OLD RECORD WAS
76.2-INCHES DURING THE 1946-47 SEASON. TURNER HAD 72.1-INCHES OF
SNOW. THEIR RECORD THROUGH THE END OF FEBRUARY IS 74.2-INCHES IN
2010-11.
AFTER A WET FALL, GREAT FALLS RECEIVED ONLY 0.99 OF PRECIPITATION
SINCE NOVEMBER 29, 2019. THROUGH MARCH 10, 2020, THIS WAS A 103-DAY
STREAK WITH LESS THAN ONE-INCH OF ACCUMULATED MOISTURE. THIS IS THE
LONGEST SUCH STREAK SINCE A 175-DAY STRETCH STARTING SEPTEMBER 17,
2003. THE RECORD FOR ONE-INCH OR LESS ACCUMULATION IS 188 DAYS
STARTING SEPTEMBER 2, 1904.
HELENA HAS HAD ONLY 2.00 IN A 154-DAY STRETCH STARTING OCTOBER 10,
2019. THIS WAS THEIR LONGEST STREAK OF SUCH AN AMOUNT SINCE A 165-
DAY STREAK STARTING AUGUST 6, 2011.
########
MARCH...
TEMPERATURES OVER THE AREA AVERAGED SLIGHTLY BELOW NORMAL. THE FIRST
70F DAY OCCURRED ON THE 6TH, WHICH WAS ABOUT A MONTH EARLIER THAN
NORMAL. FORT BENTON AND LOMA REACHED 72F. COOLER CONDITIONS FOLLOWED
WITH SOME SNOW ON THE 7TH. FROM THE 11TH THROUGH 22ND PERIODS OF
HEAVY SNOW FELL, AND THE COLDEST TEMPERATURES OF THE MONTH OCCURRED.
BADGER PASS AND NEVADA RIDGE FELL TO -15F ON THE 15TH. TEMPERATURES
WERE AS MUCH AS 40 DEGREES BELOW NORMAL DURING THIS TIME. THE REST
OF THE MONTH AVERAGED A FEW DEGREES ABOVE AND BELOW NORMAL, WITH
SNOW FALLING AGAIN ON THE 31ST. THE HI-LINE EXPERIENCED THE GREATEST
NEGATIVE DEPARTURES FROM NORMAL. CUT BANK AVERAGED 3.9F FOR THE
MONTH. WEST YELLOWSTONE AVERAGED 1.1F ABOVE NORMAL. THIS WAS ONE
SMALL AREA WHERE TEMPERATURES AVERAGED ABOVE NORMAL.
PRECIPITATION WAS GENERALLY SLIGHTLY BELOW NORMAL. THERE WERE AREAS
OF ABOVE NORMAL IN THE SOUTHWEST AND THE ROCKY MOUNTAIN FRONT. THE
HIGHEST AMOUNTS FELL OVER PORTIONS OF THE SOUTHWEST. A SWATH OF THE
ROCKY MOUNTAIN FRONT HAD DOUBLE THEIR NORMAL MARCH MOISTURE.
THERE WERE NOTABLE SNOWFALL TOTALS. THE GREATEST MONTHLY TOTAL WAS
26.9-INCHES AT CHOTEAU. THIS WAS THEIR SECOND HIGHEST TOTAL FOR
MARCH. IN 1898 THEY RECEIVED 36-INCHES. BOZEMAN AIRPORT (18.1-IN)
HAD THEIR 6TH HIGHEST MARCH TOTAL. GREAT FALLS (21.3-IN) HAD THEIR
9TH HIGHEST TOTAL FOR MARCH, AND MOST SINCE 2005.
########
APRIL...
OVERALL, TEMPERATURES IN APRIL AVERAGED BELOW NORMAL. UPPER LEVEL
FLOW WAS GENERALLY FROM THE NORTHWEST. PRECIPITATION WAS BELOW
NORMAL, WITH POCKETS OF ABOVE NORMAL ALONG THE ROCKY MOUNTAIN FRONT,
AND IN EASTERN CHOUTEAU AND EASTERN FERGUS COUNTIES. WIND AVERAGES
WERE NEAR NORMAL.
TEMPERATURES OVER THE AREA AVERAGED BELOW NORMAL. TEMPERATURES
STRUGGLED TO RISE TO ABOVE NORMAL VALUES UNTIL NEAR THE END OF THE
MONTH. WHILE SOME AERAS SAW THEIR FIRST 70F DAY ON THE 21ST, THE
BIGGER WARM-UP DID NOT OCCUR UNTIL THE 29TH, WITH SEVERAL LOCATIONS
PUSHING ABOVE 80F. THE MONTH STARTED WITH VERY COLD TEMPERATURES AND
SNOW. HIGH TEMPERATURES IN THE TEENS WERE SOME OF THE COLDEST HIGH
TEMPERATURES OF RECORD FOR THE START OF APRIL. ROCKY BOY FELL TO
-14F ON THE 2ND, FOR THE LOWEST AREA TEMPERATURE OF THE MONTH. WINDY
AND WARMER CONDITIONS PREVAILED ON THE 7TH, WITH GUSTS OF 62 MPH
NEAR FORT BENTON. SNOW FELL OVER THE REGION ON THE 11TH AND 12TH.
ULM PICKED UP 7-INCHES, WHILE 17-INCHES FELL IN THE HELENA AREA AND
10-INCHES AT BYNUM. TEMPERATURES AGAIN FELL BELOW ZERO, WITH -3F
RECORDED AT GREAT FALLS ON THE 12TH.
THERE WERE NOTABLE SNOWFALL TOTALS. THE GREATEST MONTHLY TOTAL WAS
25.8-INCHES AT NEAR LEWISTOWN. BOZEMAN AIRPORT (10.2-IN) HAD THEIR
8TH HIGHEST APRIL TOTAL.
SOME AREAS CONTINUED TO HAVE HEAVY SNOWFALL IN APRIL, SO SEASONAL
SNOWFALL RECORDS CONTINUE TO BE SET. THE FOLLOWING SHOWS THE CURRENT
SNOWFALL FOR THE SEASON.
SEASON THROUGH APRIL 30 (INCHES OF SNOW) CURRENT PREV
RECORD RECORD FOR SEASON CHOTEAU 110.3 92.9 2017-18
92.9 2017-18 *** CUT BANK 99.3 76.2 1946-47 76.2 1946-47
*** SUN RIVER 89.4 86.0 1966-67 93.8 1966-67 TURNER
82.2 74.2 2009-10 74.2 2009-10 ***
*** THESE LOCATIONS HAVE ALREADY SET NEW SNOWFALL RECORDS FOR THE
SEASON.
########
MAY...
FOR MAY, THE AVERAGE UPPER LEVEL FLOW WAS GENERALLY FROM THE WEST
OVER MONTANA. IN THE AREA, TEMPERATURES NEAR TO SLIGHTLY BELOW
NORMAL, WITH PRECIPITATION MOSTLY NEAR NORMAL. WIND AVERAGES WERE
ABOVE NORMAL.
THE MONTH BEGAN WITH NEAR NORMAL TEMPERATURES, COOLING TO A PERIOD
OF BELOW NORMAL TEMPERATURES THROUGH THE 15TH. THE COOL AIR SET A
RECORD LOW AT GREAT FALLS (26F) ON THE 5TH, WHILE YELLOW MULE
(GALLATIN) DROPPED TO 16F ON THE 7TH. STRONG WINDS AND HEAVY RAIN
OCCURRED FROM THE 6TH-8TH. AMOUNTS OF UP TO TWO INCHES FELL THROUGH
CENTRAL MONTANA. HEAVY SNOW FELL AS WELL. SHOWDOWN REPORTED A FOOT,
WITH 11-INCHES AT LEWISTOWN AND 10-INCHES AT HIGHWOOD. MORE HEAVY
RAIN FELL IN THE CLANCY AREA ON THE 12TH, WITH UP TO 1.5-INCHES OF
PRECIPITATION. SEVERE THUNDERSTORMS DEVELOPED ON THE 18TH. WIND
GUSTS REACHED 69 MPH NEAR POWER AND 73 MPH NEAR HILGER. SEVERE
THUNDERSTOMS AGAIN ON THE 19TH PRODUCED 1.25-INCH HAIL NEAR
LEWISTOWN. ON THE 20TH, SEVERE THUNDERSTORMS PRODUCED 1-INCH HAIL
NEAR VAUGHN. A LARGE STORM SYSTEM BROUGHT HEAVY RAIN TO MUCH OF THE
AREA ON THE 21ST. OVER 2.5-INCHES OF RAIN FELL OVER THE ROCKIES AND
ADJACENT PLAINS. GUSTY WINDS DURING THIS STORM WERE AS HIGH AS 61
MPH AT CUT BANK AND 56 MPH AT GREAT FALLS. AFTER A SHORT PERIOD WITH
NEAR NORMAL TEMPERATURES, THE END OF THE MONTH WARMED UP. A RECORD
HIGH TEMPERATURE WAS SET AT DILLON AND ENNIS ON THE 30TH. ON THE
31ST. STRONG WINDS BEHIND A COLD FRONT GUSTED TO 66 MPH AT CUT BANK.
########
JUNE...
FOR JUNE, THE AVERAGE UPPER LEVEL FLOW WAS GENERALLY FROM THE WEST-
SOUTHWEST, WHICH WAS NORMAL FOR THE MONTH. IN THE AREA, TEMPERATURES
AVERAGED NEAR TO SLIGHTLY BELOW NORMAL, WITH PRECIPITATION MOSTLY
ABOVE NORMAL. WIND AVERAGES WERE NEAR TO ABOVE NORMAL.
THE MONTH BEGAN WITH NEAR NORMAL TEMPERATURES, COOLING TO A PERIOD
OF BELOW NORMAL ON THE 7TH. THUNDERSTORMS MOVED THROUGH THE BOZEMAN
AREA ON THE 6TH, WITH GUSTS REACHING 57-MPH, WHICH WAS THEIR
STRONGEST JUNE GUST SINCE 2000. A STORM SYSTEM BROUGHT COOLER AIR
AND HEAVY PRECIPITATION TO THE AREA FROM THE 7TH-8TH. MALMSTROM AFB
RECORDED TWO INCHES OF RAIN, WITH 1.70-INCHES NEAR WISDOM. HIGHER
ELEVATIONS REPORTED SNOW, WITH 19-INCHES AT ALBRO LAKE AND 12-INCHES
AT DARKHORSE LAKE. EVEN POLARIS MEASURED THREE INCHES. THE COOL AIR
CAUSED THE TEMPERATURE TO MAX-OUT AT 49F AT BOZEMAN ON THE 17TH.
THIS TIED THEIR DAILY COOLEST TEMPERATURE AND IS ONE OF THE COOLEST
LATE-JUNE HIGH TEMPERATURES OF RECORD AT BOZEMAN.
########
JULY...
DURING JULY, THE AVERAGE UPPER LEVEL FLOW WAS GENERALLY FROM THE
WEST, WHICH WAS NORMAL FOR THE MONTH. IN THE AREA, TEMPERATURES
AVERAGED NEAR TO SLIGHTLY BELOW NORMAL, WITH PRECIPITATION MOSTLY
BELOW NORMAL. WIND AVERAGES WERE NEAR TO ABOVE NORMAL.
ALTHOUGH THERE WERE SOME WARMER DAYS, TEMPERATURES GENERALLY
AVERAGED BELOW NORMAL FOR THE FIRST 20 DAYS OF JULY. THUNDERSTORMS
REGULARLY OCCURRED DURING THIS TIME, TOO. THE FIRST 100F DAY OF THE
SEASON OCCURRED ON JULY 22ND WITH ARMELLS CREEK AND VALENTINE
REACHING 100F. THIS FIRST OCCURRENCE WAS 15-DAYS LATER THAN THE
AVERAGE OF JULY 7. LAST YEARS FIRST 100F DAY OF THE SEASON WAS ON
JULY 23. A COLD FRONT TRIGGERED THUNDERSTORMS ON THE 23RD, WITH WIND
GUSTS TO 66-MPH NEAR BELGRADE. THUNDERSTORMS IN THE SOUTHWEST
PRODUCED HEAVY RAIN ON THE 24TH. RAINFALL OF UP TO ONE-INCH FELL
AROUND GRANT (BEAVERHEAD), WHILE 1.5 TO A LITTLE OVER 2-INCHES FELL
FROM ENNIS SOUTH THROUGH CAMERON. TEMPERATURES WARMED TO ABOVE
NORMAL VALUES TO END THE MONTH. A 100F TEMPERATURE WAS AGAIN
REPORTED ON THE 30TH 19 MILES SOUTH OF RUDYARD. SEVERE THUNDERSTORMS
ON THE 31ST PRODUCED 2-INCH HAIL NEAR LOTHAIR (LIBERTY), WITH
SIGNIFICANT CROP AND PROPERTY DAMAGE REPORTED.
AS FOR PRECIPITATION, DRY AREAS WERE VERY DRY. CUT BANK RECORDED
ONLY A TENTH OF AN INCH, WHICH WAS THEIR 10 DRIEST AND DRIEST JULY
SINCE 2005.
########
AUGUST...
THE AVERAGE UPPER LEVEL FLOW WAS GENERALLY FROM THE WEST, WHICH WAS
NORMAL FOR THE MONTH. THE RIDGE OVER THE CENTRAL UNITED STATES WAS
STRONGER THAN NORMAL. TEMPERATURES AVERAGED ABOVE NORMAL WHILE
PRECIPITATION WAS BELOW NORMAL. WIND AVERAGES WERE NEAR OR BELOW
NORMAL.
THE FIRST SIX DAYS OF AUGUST HAD ABOVE NORMAL TEMPERATURES, BELOW
NORMAL FOR THE NEXT WEEK AND ABOVE NORMAL FOR THE REST OF THE MONTH.
A COLD FRONT PASSING THROUGH THE AREA ON THE 6TH BROUGHT SEVERE
THUNDERSTORMS WITH GUSTS TO 64-MPH AT TOWNSEND AND 59-MPH AT GREAT
FALLS. MUCH WARMER AIR RETURNED BY THE 16TH, WITH A 102F TEMPERATURE
RECORDED AT FORT BENTON. SEVERE THUNDERSTORMS ON THE 20TH PRODUCED
AROUND ONE-INCH OF RAIN IN 30 MINUTES NEAR CHOTEAU. A STRONGER COLD
FRONT BROUGHT MUCH COOLER AIR TO THE AREA ON THE 20TH, WITH SOME
SNOW AT HIGHER ELEVATIONS IN THE SOUTHWEST ON THE 31ST.
SEVERE DRYNESS REMAINED ACROSS MUCH OF THE AREA. SEVERAL LOCATIONS
HAD THEIR DRIEST AUGUST SINCE 2017, WHILE HAVRE HAD THEIR DRIEST
SINCE 1969.
########
SEPTEMBER...
DURING SEPTEMBER, AVERAGE UPPER LEVEL FLOW FROM THE NORTHWEST
BROUGHT ABOVE NORMAL TEMPERATURES, BELOW NORMAL PRECIPITATION AND
SLIGHTLY ABOVE NORMAL WIND SPEEDS.
THE FIRST SIX DAYS OF SEPTEMBER HAD GENERALLY ABOVE NORMAL
TEMPERATURES, WITH HIGHS OF 100F ON THE 5TH AT LOMA AND BOZEMAN.
THE LAST YEAR IN WHICH A 100F VALUE WAS RECORDED IN SEPTEMBER IN THE
AREA WAS IN 2001, WHEN FORT BENTON REPORTED THE LATEST EVER 100F IN
MONTANA ON THE 25TH. A SOMEWHAT COOLER PERIOD PERSISTED FOR THE NEXT
WEEK, LOWS DROPPING INTO THE 20S MOST ARAS, AND YELLOW MULE REPORTED
THE AREAS LOWEST ON THE 8TH (14F). SOME SNOW WAS REPORTED AT HIGHER
ELEVATIONS. WARMER CONDITIONS RETURNED, WITH MOST OF THE REST OF THE
MONTH RECORDING ABOVE NORMAL TEMPERATURES AND LITTLE PRECIPITATION.
MANY AREAS RECORDED THEIR FIRST SEASONAL FREEZING TEMPERATURE ON
SEPTEMBER 8. AT GREAT FALLS, THIS WAS THE 6TH EARLIEST OF RECORD AND
EARLIEST SINCE THE LATE AUGUST SNOWS AND COLD OF 1992. THE FREEZE-
FREE SEASON WAS 107 DAYS AT GREAT FALLS, THE 9TH SHORTEST OF RECORD
AND SHORTEST SINCE 2009. THEIR AVERAGE LENGTH IS 122 DAYS. AT
DILLON, THE LOW OF 25F ON THE 8TH WAS THEIR 2ND EARLIEST WITH A
TEMPERATURE OF 25F OR LOWER SO EARLY IN THE SEASON. AT GREAT FALLS,
THEIR LOW OF 28F WAS THE 2ND EARLIEST LOW OF 28F OR LOWER SO EARLY
IN THE SEASON. THE EARLIEST WAS SEPT 6, 1929.
THE DRY AREAS REMAINED DRY. BOZEMAN AND HELENA HAD THEIR DRIEST
SEPTEMBER SINCE 2012. FOR THE PERIOD FROM JULY THROUGH SEPTEMBER,
THIS WAS THE 6TH DRIEST AT CUT BANK (0.99). DILLON RECEIVED ONLY
0.92, WHICH WAS THEIR THIRD DRIEST. AT GREAT FALLS, THE JUL-SEP
PERIOD PRODUCED 1.19-INCHES OF RAIN. THIS WAS THE DRIEST SINCE 1979.
NORMAL IS 4.49-INCHES. HELENA HAD THEIR DRIEST PAST THREE MONTHS OF
RECORD, PICKING UP ONLY 0.58. THE PREVIOUS DRIEST SUMMER PERIOD AT
HELENA WAS IN 1919.
THERE WERE SOME VERY WINDY DAYS DURING SEPTEMBER. ON THE 2ND,
BOZEMAN HAD A DAILY WIND AVERAGE OF 13.9-MPH, WHICH WAS THEIR
WINDIEST SEPTEMBER DAY SINCE 1999. CUT BANK AVERAGED 30.1-MPH ON THE
24TH, WHICH WAS THEIR WINDIEST SEPTEMBER DAY SINCE 1984. A PEAK GUST
OF 69-MPH ON THE 24TH WAS CUT BANKS THIRD HIGHEST SEPTEMBER GUST OF
RECORD AND HIGHEST SINCE 1960. DILLONS DAILY WIND AVERAGE OF 21.7-
MPH ON THE 7TH WAS THEIR WINDIEST SEPTEMBER DAY SINCE 1954 AND
SECOND HIGHEST DAILY SEPTEMBER AVERAGE OF RECORD.
########
OCTOBER...
UPPER LEVEL FLOW CONTINUED FROM THE NORTHWEST. TEMPERATURES AVERAGED
ABOVE NORMAL WITH BELOW NORMAL PRECIPITATION.
THE FIRST TWELVE DAYS OF OCTOBER HAD GENERALLY ABOVE NORMAL
TEMPERATURES. RECORD HIGH TEMPERATURES OCCURRED AT SEVERAL LOCATIONS
FROM THE 4TH THROUGH 8TH. THE DRYNESS FROM SEPTEMBER PERSISTED
THROUGH THIS PERIOD AS WELL. VERY WINDY CONDITIONS PREVAILED FROM
THE 10TH THROUGH 16TH. COOLER CONDITIONS, THEN MUCH COOLER WITH SNOW
PREVAILED FROM THE 11TH THROUGH THE 26TH. RECORD AMOUNTS OF SNOW
FELL BETWEEN THE 18TH AND 23RD, WITH RECORD COLD TEMPERATURES FROM
THE 22ND THROUGH 26TH. THE COLDEST TEMPERATURE FOR THE MONTH
OCCURRED NEAR RINGLING ON THE 26TH. A LOW OF -29F TIED WITH POTOMAC
(RECORDED ON THE 25TH) FOR THE SECOND COLDEST TEMPERATURE RECORDED
IN ANY OCTOBER IN MONTANA. THE COLDEST WAS -30F AT SUMMIT ON OCTOBER
31, 1935. THE MONTH ENDED WITH TEMPERATURES ABOVE NORMAL AND MOST OF
THE SNOW MELTED AT LOWER ELEVATIONS.
SNOWFALL DURING THE MONTH SET RECORDS AT MANY LOCATIONS. NOT ONLY
DAILY, BUT NEW MONTHLY RECORDS WERE SET. CUT BANK AND GREAT FALLS
SET NEW MONTHLY RECORDS. 28-INCHES AT GREAT FALLS MAKES THIS OCTOBER
THE EIGHTH SNOWIEST OF ANY MONTH OF RECORD. HELENA RECORDED THEIR
SNOWIEST OCTOBER SINCE 1925.
DILLON HAD THEIR WINDIEST OCTOBER SINCE 1990. GENERALLY STRONGER
THAN NORMAL WINDS HAS PRODUCED THE WINDIEST CALENDAR-YEAR THROUGH
OCTOBER SINCE 1989 AT DILLON, SINCE 1999 AT CUT BANK AND GREAT
FALLS, AND SINCE 2002 AT HAVRE.
########
NOVEMBER...
UPPER LEVEL FLOW DURING NOVEMBER WAS FROM A WESTERLY DIRECTION.
THE FIRST FIVE DAYS OF NOVEMBER HAD ABOVE NORMAL TEMPERATURES. A
HIGH TEMPERATURE OF 81F WAS RECORDED AT ARMELLS CREEK ON THE 2ND.
THIS WAS THE FIRST 80F OR HIGHER READING IN THE AREA IN NOVEMBER
SINCE 1999. VALENTINE RECORDED 83F ON THE 7TH IN 1999.
AS A LARGE STORM SETTLED IN, A COLDER PERIOD PERSISTED FROM THE 6TH
THROUGH 15TH. HEAVY SNOW AND BLIZZARD CONDITIONS OCCURRED OVER NORTH
CENTRAL MONTANA ON THE 7TH AND 8TH. GUSTS REACHED 65-MPH WITH SNOW
AMOUNTS OF AROUND A FOOT IN MANY LOCATIONS. POWER OUTAGES OCCURRED
AS ICE ACCUMULATED ON LINES, THEN THEY WERE WHIPPED BY THE STRONG
WINDS. THIS CAUSED SOME POLES TO SNAP. SOME AREAS RECORDED BELOW
ZERO LOWS ON THE 12TH. WARMER CONDITIONS RETURNED, ALONG WITH WIND.
FOR MOST OF THE REST OF THE MONTH, IT WAS DRY, MILD AND WINDY. SOME
OF THE NOTABLE WIND CONDITIONS ARE SUMMARIZED LATER IN THIS REPORT.
PRECIPITATION WAS BELOW NORMAL PRECIPITATION, EXCEPT OVER THE HI-
LINE. THE SNOWSTORM AND BLIZZARD FROM THE 7TH-9TH MAINLY AFFECTED
NORTHCENTRAL MONTANA. AS IN THE PAST THREE MONTHS, DRY AREAS WERE
VERY DRY. BOZEMAN HAD THEIR DRIEST NOVEMBER SINCE 2006.
WINDS SPEED AVERAGES WERE MOSTLY ABOVE NORMAL ACROSS THE REGION.
THE STRONGEST AREA AVERAGE WIND SPEED WAS 28.0-MPH AT DEEP CREEK
RAWS, WHICH IS THEIR HIGHEST NOVEMBER AVERAGE SINCE RECORDS BEGAN IN
2003. CUT BANK HAD THE HIGHEST AVERAGE AT AN AIRPORT (18.4-MPH),
THEIR 6TH HIGHEST OF RECORD FOR NOVEMBER.
########
DECEMBER...
NORTHWEST FLOW DOMINATED MOST OF THE MONTH DURING DECEMBER. THIS IS
NORMAL, BUT A RIDGE ALONG THE WEST COAST WAS STRONGER THAN NORMAL.
TEMPERATURES AVERAGED MUCH ABOVE NORMAL, WITH BELOW NORMAL
PRECIPITATION. WIND AVERAGES WERE ABOVE NORMAL.
THE FIRST TEN DAYS OF DECEMBER HAD ABOVE NORMAL TEMPERATURES AND
BREEZY CONDITIONS. A HIGH TEMPERATURE OF 68F WAS RECORDED AT ARMELLS
CREEK ON THE 8TH. GREAT FALLS LOW TEMPERATURE OF 51F ON 8TH WAS
THEIR SECOND WARMEST DECEMBER MINIMUM TEMPERATURE OF RECORD. THE
WARMEST IS 53F ON DEC 12, 1980. WIND GUSTS ALSO REACHED 61-MPH AT
GREAT FALLS AND THIS WAS THE SIXTH GUST OF 60-MPH OR MORE FOR THE
YEAR, LAST SEEN IN 2012. A SHORT PERIOD WITH BELOW NORMAL
TEMPERATURES SET IN THROUGH THE 14TH. SOME LIGHTER AMOUNTS OF SNOW
FELL OVER MUCH OF THE AREA. TEMPERATURES PUSHED BACK ABOVE NORMAL ON
THE 15TH, AND MOSTLY REMAINED THERE FOR THE REST OF THE MONTH.
STRONG AND GUSTY WINDS WERE A COMMON FACTOR OVER THE PLAINS. ON THE
18TH, BROWNING HAD A GUST OF 62-MPH, WITH GUSTS TO 71-MPH WEST OF
BYNUM ON THE 19TH.
A COLD FRONT MOVED THROUGH ON THE 22ND AND BROUGHT ABOUT A FOOT OF
SNOW TO THE NORTH SLOPES OF THE LITTLE BELTS. LITTLE SNOW FELL OVER
LOWER ELEVATIONS. WINDS AND WARMER TEMEPRATURES RETURNED BY THE 24TH
AND LASTED THROUGH THE END OF THE MONTH. WITH INVERSIONS OVER THE
SOUTHWEST AT THE END OF THE MONTH, A TEMPERATURE OF -26F WAS
RECORDED NEAR WEST YELLOWSTONE ON THE 29TH.
WIND SPEED AVERAGES WERE MOSTLY ABOVE NORMAL ACROSS THE REGION. THE
STRONGEST AREA AVERAGE WIND SPEED WAS 25.6-MPH AT DEEP CREEK RAWS,
WHICH IS THEIR THIRD HIGHEST DECEMBER AVERAGE SINCE RECORDS BEGAN IN
2003, AND 3-MPH ABOVE NORMAL. LEWISTOWN HAD A GUST OF 69-MPH, WHICH
SET A NEW ALL-TIME HIGH GUST FOR DECEMBER. THEIR PREVIOUS RECORD WAS
68-MPH ON DECEMBER 4, 1995. THIS WAS ALSO THEIR WINDIEST DAY SINCE
JULY 14, 2002. ON THE 20TH, LEWISTOWNS WIND AVERAGE WAS 24-MPH.
$$
&&
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