Climatological Report (Monthly)
Issued by NWS
Issued by NWS
589
CXUS55 KRIW 092105 CCA
CLMLND
CLIMATE REPORT
NATIONAL WEATHER SERVICE RIVERTON WY
121 PM MST FRI JAN 09 2026
...PRELIMINARY MONTHLY CLIMATE SUMMARY FOR LANDER FOR THE MONTH OF
DECEMBER 2025...
...OFFICIAL CLIMATE DATA FOR THE MONTH OF DECEMBER 2025 WILL BE
AVAILABLE IN APPROXIMATELY 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
...LANDER WAS DRIER WITH RECORD WARMTH IN DECEMBER....
THE AVERAGE TEMPERATURE FOR LANDER IN DECEMBER WAS 36.5 DEGREES
WHICH WAS 14.9 DEGREES ABOVE NORMAL. IT WAS THE WARMEST DECEMBER
SINCE RECORDS BEGAN IN 1892. THE WARMEST READING FOR THE MONTH WAS
65 DEGREES ON THE 24TH AND BROKE THE 2005 RECORD OF 55. IT ALSO TIED
FOR THE ALL-TIME RECORD HIGH FOR THE MONTH. THE 12TH HIGH OF 57
DEGREES TIED THE 1995, 1929 AND 1924 RECORD. THE 15TH HIGH OF 62
BROKE 60 FROM 1939. THE 22ND HIGH OF 59 TIED 1917. THE 23RD HIT 60
DEGREES AND BROKE THE 1901 RECORD OF 57. THE COLDEST TEMPERATURE WAS
5 DEGREES ON THE 1ST.
PRECIPITATION FOR THE MONTH WAS 0.28 INCHES...WHICH IS 44 PERCENT OF
NORMAL. THE WETTEST 24-HOUR PERIOD WAS THE 2ND-3RD WHEN 0.18 INCHES
OF PRECIPITATION FELL. NO PRECIPITATION OR SNOWFALL RECORDS WERE
BROKEN THIS MONTH.
THE SNOWFALL FOR THE MONTH WAS 2.6 INCHES WHICH IS 28 PERCENT OF
NORMAL. THE SNOWIEST 24-HOUR PERIOD WAS ON THE 2ND-3RD WHEN 2.6
INCHES FELL. THE HIGHEST WIND GUST WAS 92 MPH AND OCCURRED ON THE
17TH FROM THE SOUTH.
...THE LANDER WY CLIMATE SUMMARY FOR THE MONTH OF DECEMBER 2025...
CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1891 TO 2026
WEATHER OBSERVED NORMAL DEPART LAST YEAR`S
VALUE DATE(S) VALUE FROM VALUE
NORMAL
..............................................................
TEMPERATURE (F)
RECORD
HIGH 65 12/11/1937
12/10/1933
LOW -40 12/19/1924
HIGHEST 65R 12/24
LOWEST 5 12/01
AVG. MAXIMUM 49.0R 32.9 16.1
AVG. MINIMUM 24.1R 10.2 13.9
MEAN 36.5R 21.6 14.9
DAYS MAX >= 90 0
DAYS MAX <= 32 1
DAYS MIN <= 32 27
DAYS MIN <= 0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 2.06 1909
MINIMUM T 1933
TOTALS 0.28 0.63 -0.35 0.04
DAILY AVG. 0.01 0.02 -0.01
DAYS >= .01 5
DAYS >= .10 1
DAYS >= .50 0
DAYS >= 1.00 0
GREATEST
24 HR. TOTAL 0.18 12/02 TO 12/03
STORM TOTAL 0.14
SNOWFALL (INCHES)
TOTALS 2.6 9.3 -6.7
SINCE 7/1 3.7 31.9 -28.2
SNOWDEPTH AVG. 0
DAYS >= 1.0 1
DEGREE DAYS
HEATING TOTAL 874 1347 -473
SINCE 7/1 2244 3177 -933
COOLING TOTAL 0 0 0
SINCE 1/1 569 485 84
..............................................................
WIND (MPH)
AVERAGE WIND SPEED 8.3
RESULTANT WIND SPEED/DIRECTION 3/240
HIGHEST WIND SPEED/DIRECTION 59/230 DATE 12/17
HIGHEST GUST SPEED/DIRECTION 92/180 DATE 12/17
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.13
NUMBER OF DAYS FAIR 28
NUMBER OF DAYS PC 3
NUMBER OF DAYS CLOUDY 0
AVERAGE RH (PERCENT) 54
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 0 MIXED PRECIP 0
HEAVY RAIN 0 RAIN 0
LIGHT RAIN 4 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 5 SLEET 0
FOG 4 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 2026. THE AVERAGE HIGH TEMPERATURE ON THE
FIRST OF THE MONTH IS 32 DEGREES...AND THE AVERAGE LOW TEMPERATURE
IS 9 DEGREES. THE AVERAGE HIGH BY THE END OF THE MONTH IS 33
DEGREES...AND THE AVERAGE LOW TEMPERATURE IS 11. THE AVERAGE MONTHLY
PRECIPITATION IS 0.51 INCHES. THE AVERAGE SNOWFALL IS 8.2 INCHES.
$$