873
CXUS55 KRIW 011642
CLMCPR
CLIMATE REPORT
NATIONAL WEATHER SERVICE RIVERTON WY
1032 AM MDT MON JUN 01 2026
...PRELIMINARY MONTHLY CLIMATE SUMMARY FOR CASPER FOR THE MONTH OF
MAY 2026...
...OFFICIAL CLIMATE DATA FOR THE MONTH OF MAY 2026 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
..MAY IN CASPER WAS WARMER AND DRIER THAN NORMAL
AVERAGE TEMPERATURE FOR CASPER IN MAY WAS 53 DEGREES WHICH IS 1
DEGREE ABOVE NORMAL. THE WARMEST READING OF THE MONTH WAS 92 DEGREES
ON THE 13TH. THIS BROKE THE 2013 RECORD OF 88. IT ALSO SET A NEW
EARLIEST 90-DEGREE DAY FOR MAY. PREVIOUSLY IT WAS MAY 26TH 2006. THE
11TH HIT 85 AND BROKE 83 FROM 1940. THE COLDEST READING FOR THE
MONTH WAS 18 DEGREES ON THE 6TH. THIS BROKE THE 2010 RECORD OF 20.
THE 19TH LOW OF 26 BROKE 27 FROM 1968..
TOTAL PRECIPITATION FOR THE MONTH WAS 1.67 INCHES...WHICH IS 76
PERCENT OF NORMAL. THE WETTEST 24-HOUR PERIOD DURING THE MONTH WAS
ON THE 17TH-18TH WITH 0.69INCHES. NO PRECIPITATION OR SNOWFALL
RECORDS WERE BROKEN THIS MONTH.
THE SNOWFALL FOR THE MONTH WAS 2.5 INCHES WHICH IS 96 PERCENT OF
NORMAL. THE SNOWIEST 24-HOURS WAS ON THE 18 WITH 2.5 INCHES. THE
HIGHEST WIND GUST WAS 58 MPH FROM THE SOUTHWEST ON THE 15TH.
..THE CASPER WY CLIMATE SUMMARY FOR THE MONTH OF MAY 2026
CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1939 TO 2026
WEATHER OBSERVED NORMAL DEPART LAST YEAR'S
VALUE DATE(S) VALUE FROM VALUE
NORMAL
..........................................................
TEMPERATURE (F)
RECORD
HIGH 95 05/29/2003
LOW 16 05/12/1953
HIGHEST 92 05/13
LOWEST 18 05/06
AVG. MAXIMUM 69.2 66.8 2.4
AVG. MINIMUM 36.9 37.1 -0.2
MEAN 53.0 52.0 1.0
DAYS MAX >= 90 1
DAYS MAX <= 32 0
DAYS MIN <= 32 10
DAYS MIN <= 0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 6.46 1978
MINIMUM 0.30 2020
TOTALS 1.67 2.21 -0.54 1.28
DAILY AVG. 0.05 0.07 -0.02
DAYS >= .01 9
DAYS >= .10 4
DAYS >= .50 2
DAYS >= 1.00 0
GREATEST
24 HR. TOTAL 0.69 05/17 TO 05/18
STORM TOTAL 0.62
SNOWFALL (INCHES)
TOTALS 2.5 2.6 -0.1
SINCE 7/1 29.6 71.7 -42.1
SNOWDEPTH AVG. 0
DAYS >= 1.0 1
DEGREE DAYS
HEATING TOTAL 365 409 -44
SINCE 7/1 5748 7361 -1613
COOLING TOTAL 1 4 -3
SINCE 1/1 1 4 -3
..........................................................
WIND (MPH)
AVERAGE WIND SPEED 10.6
RESULTANT WIND SPEED/DIRECTION 3/260
HIGHEST WIND SPEED/DIRECTION 39/220 DATE 05/13
HIGHEST GUST SPEED/DIRECTION 58/220 DATE 05/15
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.26
NUMBER OF DAYS FAIR 23
NUMBER OF DAYS PC 5
NUMBER OF DAYS CLOUDY 3
AVERAGE RH (PERCENT) 55
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 5 MIXED PRECIP 0
HEAVY RAIN 1 RAIN 3
LIGHT RAIN 15 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 2
LIGHT SNOW 3 SLEET 0
FOG 5 FOG W/VIS <= 1/4 MILE 0
HAZE 2
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
LOOKING AHEAD TO JUNE 2026. THE AVERAGE HIGH TEMPERATURE ON THE
FIRST OF THE MONTH IS 74 DEGREES...AND THE AVERAGE LOW TEMPERATURE
IS 42 DEGREES. THE AVERAGE HIGH BY THE END OF THE MONTH IS 85
DEGREES...AND THE AVERAGE LOW TEMPERATURE IS 49. THE AVERAGE MONTHLY
PRECIPITATION IS 1.34 INCHES. THE AVERAGE SNOWFALL IS 0.1 INCHES.
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