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000
CXUS55 KRIW 031918 CCA
CLMP60

CLIMATE REPORT
NATIONAL WEATHER SERVICE RIVERTON WY
1024 AM MST SAT JAN 01 2022

...PRELIMINARY MONTHLY CLIMATE SUMMARY FOR LAKE YELLOWSTONE FOR THE
MONTH OF DECEMBER 2021...

...OFFICIAL CLIMATE DATA FOR THE MONTH OF DECEMBER 2021 WILL BE
AVAILABLE APPROXIMATELY IN 60 DAYS FROM THE NATIONAL CENTERS FOR
ENVIRONMENTAL INFORMATION (HTTP://WWW.NCDC.NOAA.GOV/CDO-
WEB/DATASETS). UNOFFICIAL ASOS DAILY SUMMARIES ARE AVAILABLE ON THE
INTERNET AT HTTP://WWW.WEATHER.GOV/CLIMATE/INDEX.PHP?WFO=RIW

...LAKE YELLOWSTONE WAS WARMER AND WETTER THAN NORMAL IN DECEMBER...

THIS IS AN UPDATE AS THE FINAL DAYS DATA BECAME AVAILABLE. AVERAGE
TEMPERATURE FOR LAKE YELLOWSTONE IN DECEMBER WAS 17.8 DEGREES WHICH
WAS 4.8 DEGREES ABOVE NORMAL. THIS WAS THE 3RD WARMEST DECEMBER
SINCE RECORDS STARTED IN 1995. THE WARMEST READING OF THE MONTH WAS
41 DEGREES ON THE 2ND AND 3RD...AND BOTH DAYS BROKE PREVIOUS DAILY
RECORDS. THE 2ND BROKE 34 FROM 2012...AND THE 3RD BROKE THE 1998
RECORD OF 36. THE 4TH HIT 38 DEGREES...WHICH BROKE THE 2014 RECORD
OF 36. THE COLDEST READING WAS 12 DEGREES BELOW ZERO ON THE 17TH.

TOTAL PRECIPITATION AT LAKE YELLOWSTONE WAS 4.16 INCHES...WHICH WAS
177 PERCENT OF NORMAL...AND MAKING IT THE 3RD WETTEST DECEMBER SINCE
RECORDS STARTED IN 1995. THE WETTEST 24-HOUR PERIOD DURING THE MONTH
WAS THE 14TH WHEN 0.54 INCHES OF PRECIPITATION FELL. THIS ALSO BROKE
THE 2015 RECORD OF 0.24. THE HIGHEST WIND GUST WAS 43 MPH FROM THE
SOUTHWEST ON THE 4TH.

...THE LAKE YELLOWSTONE WY CLIMATE SUMMARY FOR THE MONTH OF DECEMBER
2021...

CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1998 TO 2021

WEATHER         OBSERVED          NORMAL  DEPART   LAST YEAR`S
                VALUE   DATE(S)   VALUE   FROM     VALUE
                                          NORMAL
..............................................................
TEMPERATURE (F)
RECORD
 HIGH             46   12/12/2014
 LOW             -34   12/21/1998
HIGHEST           41   12/02
                       12/03
LOWEST           -12   12/17
AVG. MAXIMUM    24.1               23.3     1.2
AVG. MINIMUM    11.6                2.7     9.7
MEAN            17.8               13.0     4.8
DAYS MAX >= 90     0
DAYS MAX <= 32    27
DAYS MIN <= 32    30
DAYS MIN <= 0      7

PRECIPITATION (INCHES)
RECORD
 MAXIMUM        5.15   2007
 MINIMUM        0.37   2000
TOTALS          4.16               2.35    1.81     1.24
DAILY AVG.      0.13               0.08    0.05
DAYS >= .01       25
DAYS >= .10       12
DAYS >= .50        2
DAYS >= 1.00       0
GREATEST
 24 HR. TOTAL   0.54   12/14 TO 12/14
 STORM TOTAL    0.54


DEGREE DAYS
HEATING TOTAL   1454               1612    -158
 SINCE 7/1      4495               5119    -741
COOLING TOTAL      0                          0
 SINCE 1/1         0                  0       0

..............................................................

WIND (MPH)
AVERAGE WIND SPEED              4.0
RESULTANT WIND SPEED/DIRECTION   1/240
HIGHEST WIND SPEED/DIRECTION    21/260    DATE  12/04
HIGHEST GUST SPEED/DIRECTION    43/220    DATE  12/04

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.00
NUMBER OF DAYS FAIR           13
NUMBER OF DAYS PC              0
NUMBER OF DAYS CLOUDY          0

AVERAGE RH (PERCENT)     80

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       0
LIGHT RAIN                0     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW               25     SLEET                      0
FOG                       0     FOG W/VIS <= 1/4 MILE      0
HAZE                      0

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

LOOKING AHEAD TO JANUARY 2022...THE AVERAGE HIGH TEMPERATURE ON THE
FIRST OF THE MONTH IS 23 DEGREES...AND THE AVERAGE LOW TEMPERATURE
IS 1 DEGREE. THE AVERAGE HIGH BY THE END OF THE MONTH IS 23 DEGREES
AND THE AVERAGE LOW TEMPERATURE IS 0 DEGREES. THE AVERAGE MONTHLY
PRECIPITATION IS 1.80 INCHES.

$$