857
CXUS55 KRIW 011705
CLMP60

CLIMATE REPORT
NATIONAL WEATHER SERVICE RIVERTON WY
1105 AM MDT THU OCT 01 2026

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

...THE LAKE YELLOWSTONE WY CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2026...

CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1998 TO 2026

WEATHER         OBSERVED          NORMAL  DEPART   LAST YEAR`S
                VALUE   DATE(S)   VALUE   FROM     VALUE
                                          NORMAL
..............................................................
TEMPERATURE (F)
RECORD
 HIGH             83   09/07/2022
 LOW              13   09/24/2000
HIGHEST           72   09/06
LOWEST            25   09/15
AVG. MAXIMUM    61.3               60.5     0.8
AVG. MINIMUM    32.9               30.3     2.6
MEAN            47.1               45.4     1.7
DAYS MAX >= 90     0
DAYS MAX <= 32     0
DAYS MIN <= 32    16
DAYS MIN <= 0      0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM        4.09   2013
 MINIMUM        0.21   2018
TOTALS          1.71               1.57    0.14     1.46
DAILY AVG.      0.06               0.05    0.01
DAYS >= .01       11
DAYS >= .10        6
DAYS >= .50        1
DAYS >= 1.00       0
GREATEST
 24 HR. TOTAL   0.84   09/17 TO 09/18
 STORM TOTAL    0.53

DEGREE DAYS
HEATING TOTAL    507                588     -81
 SINCE 7/1       875               1230    -355
COOLING TOTAL      0                  0       0
 SINCE 1/1         2                  0       2
..............................................................

WIND (MPH)
AVERAGE WIND SPEED              2.7
RESULTANT WIND SPEED/DIRECTION   0/270
HIGHEST WIND SPEED/DIRECTION    20/270    DATE  09/13
HIGHEST GUST SPEED/DIRECTION    33/270    DATE  09/13

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.00
NUMBER OF DAYS FAIR           30
NUMBER OF DAYS PC              0
NUMBER OF DAYS CLOUDY          0

AVERAGE RH (PERCENT)     65

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       0
LIGHT RAIN               11     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     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.

$$