854
CXUS55 KRIW 012027
CLMRIW
CLIMATE REPORT
NATIONAL WEATHER SERVICE RIVERTON WY
212 PM MDT WED OCT 01 2025
...PRELIMINARY MONTHLY CLIMATE SUMMARY FOR RIVERTON FOR THE MONTH OF
SEPTEMBER 2025...
...OFFICIAL CLIMATE DATA FOR THE MONTH OF SEPTEMBER 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
..RIVERTON WAS WARMER AND WETTER THAN NORMAL IN SEPTEMBER.
THE AVERAGE TEMPERATURE FOR RIVERTON IN SEPTEMBER WAS 62.8 DEGREES
WHICH WAS 3.6 DEGREES ABOVE NORMAL. IT WAS THE 5TH WARMEST SEPTEMBER
SINCE RECORDS BEGAN IN 1996. THE WARMEST READING FOR THE MONTH WAS
88 DEGREES ON THE 2ND AND 3RD. THE COLDEST READING WAS 40 DEGREES ON
THE 6TH AND 16TH. NO TEMPERATURE RECORDS WERE BROKEN THIS MONTH.
PRECIPITATION FOR THE MONTH WAS 0.99 INCHES...WHICH IS 129 PERCENT
OF NORMAL. IT WAS THE 7TH WETTEST SEPTEMBER SINCE RECORDS BEGAN IN
1998. THE WETTEST 24-HOURS WAS THE 22ND WHEN 0.91 INCHES FELL. THIS
BROKE THE 2017 RECORD OF 0.43 INCHES. THE HIGHEST WIND GUST WAS 51
MPH FROM THE WEST AND OCCURRED ON THE 13TH.
..THE RIVERTON WY CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2025
CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1995 TO 2025
WEATHER OBSERVED NORMAL DEPART LAST YEAR'S
VALUE DATE(S) VALUE FROM VALUE
NORMAL
..........................................................
TEMPERATURE (F)
RECORD
HIGH 100 09/04/2022
LOW 21 09/27/1996
09/27/1996
HIGHEST 88 09/02
09/03
LOWEST 40 09/06
09/16
AVG. MAXIMUM 77.2 74.0 3.2
AVG. MINIMUM 48.3 44.4 3.9
MEAN 62.8 59.2 3.6
DAYS MAX >= 90 0
DAYS MAX <= 32 0
DAYS MIN <= 32 0
DAYS MIN <= 0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 3.01 2013
MINIMUM 0.01 2010
TOTALS 0.99 0.77 0.22 0.07
DAILY AVG. 0.03 0.03 0.00
DAYS >= .01 3
DAYS >= .10 1
DAYS >= .50 1
DAYS >= 1.00 0
GREATEST
24 HR. TOTAL 0.91 09/22 TO 09/22
STORM TOTAL 0.91
SNOWFALL (INCHES)
TOTALS 0.0 MM MM
SINCE 7/1 0.0 MM MM
SNOWDEPTH AVG. 0
DAYS >= 1.0 0
DEGREE DAYS
HEATING TOTAL 97 205 -108
SINCE 7/1 100 241 -141
COOLING TOTAL 37 31 6
SINCE 1/1 611 499 112
..........................................................
WIND (MPH)
AVERAGE WIND SPEED 7.9
RESULTANT WIND SPEED/DIRECTION 2/330
HIGHEST WIND SPEED/DIRECTION 38/250 DATE 09/21
HIGHEST GUST SPEED/DIRECTION 51/260 DATE 09/15
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.15
NUMBER OF DAYS FAIR 26
NUMBER OF DAYS PC 3
NUMBER OF DAYS CLOUDY 1
AVERAGE RH (PERCENT) 47
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 4 MIXED PRECIP 0
HEAVY RAIN 1 RAIN 2
LIGHT RAIN 10 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 0 SLEET 0
FOG 1 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 OCTOBER 2025. THE AVERAGE HIGH TEMPERATURE ON THE
FIRST OF THE MONTH IS 66 DEGREES...AND THE AVERAGE LOW TEMPERATURE
IS 38 DEGREES. THE AVERAGE HIGH BY THE END OF THE MONTH IS 51
DEGREES AND THE AVERAGE LOW TEMPERATURE IS 25. THE AVERAGE MONTHLY
PRECIPITATION IS 0.83 INCHES.
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