


Climatological Report (Monthly)
Issued by NWS
Issued by NWS
428 CXUS55 KRIW 012023 CLMGEY CLIMATE REPORT NATIONAL WEATHER SERVICE RIVERTON WY 212 PM MDT WED OCT 01 2025 ...PRELIMINARY MONTHLY CLIMATE SUMMARY FOR GREYBULL 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 ...GREYBULL IN SEPTEMBER WAS DRIER AND WARMER THAN NORMAL.... THE AVERAGE TEMPERATURE FOR GREYBULL IN SEPTEMBER WAS 64.4 DEGREES WHICH IS 3.5 DEGREES ABOVE NORMAL. IT WAS THE 4TH WARMEST SEPTEMBER SINCE RECORDS BEGAN IN 1998. THE WARMEST TEMPERATURE FOR THE MONTH WAS 93 DEGREES ON THE 2ND. THE HIGH OF 89 ON THE 21ST BROKE 86 DEGREES FROM 2013. THE COLDEST TEMPERATURE WAS 39 DEGREES ON THE 6TH AND BROKE THE 2015 RECORD OF 40 DEGREES. PRECIPITATION FOR THE MONTH WAS 0.65 INCHES...WHICH IS 78 PERCENT OF NORMAL. THE WETTEST 24-HOUR PERIOD OCCURRED ON THE 22ND WITH 0.53 INCHES AND BROKE THE 2023 RECORD OF 0.31. THE HIGHEST WIND GUST WAS 45 MPH. IT OCCURRED ON THE 4TH AND ON THE 7TH...BOTH FROM THE NORTHWEST. ...THE GREYBULL WY CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2025... CLIMATE NORMAL PERIOD: 1991 TO 2020 CLIMATE RECORD PERIOD: 1998 TO 2025 WEATHER OBSERVED NORMAL DEPART LAST YEAR`S VALUE DATE(S) VALUE FROM VALUE NORMAL .............................................................. TEMPERATURE (F) RECORD HIGH 103 09/04/2022 LOW 27 09/18/2003 09/29/1999 HIGHEST 93 09/02 LOWEST 39 09/06 AVG. MAXIMUM 81.4 76.7 4.7 AVG. MINIMUM 47.4 45.1 2.3 MEAN 64.4 60.9 3.5 DAYS MAX >= 90 4 DAYS MAX <= 32 0 DAYS MIN <= 32 0 DAYS MIN <= 0 0 PRECIPITATION (INCHES) RECORD MAXIMUM 3.21 2019 MINIMUM 0.01 2021 TOTALS 0.65 0.83 -0.18 0.38 DAILY AVG. 0.02 0.03 -0.01 DAYS >= .01 4 DAYS >= .10 1 DAYS >= .50 1 DAYS >= 1.00 0 GREATEST 24 HR. TOTAL 0.53 09/22 TO 09/22 STORM TOTAL 0.53 DEGREE DAYS HEATING TOTAL 61 169 -108 SINCE 7/1 61 189 -128 COOLING TOTAL 50 46 4 SINCE 1/1 791 742 49 .............................................................. WIND (MPH) AVERAGE WIND SPEED 5.5 RESULTANT WIND SPEED/DIRECTION 1/320 HIGHEST WIND SPEED/DIRECTION 35/340 DATE 09/04 HIGHEST GUST SPEED/DIRECTION 45/330 DATE 09/04 45/310 09/07 SKY COVER POSSIBLE SUNSHINE (PERCENT) MM AVERAGE SKY COVER 0.12 NUMBER OF DAYS FAIR 26 NUMBER OF DAYS PC 4 NUMBER OF DAYS CLOUDY 0 AVERAGE RH (PERCENT) 50 WEATHER CONDITIONS. NUMBER OF DAYS WITH THUNDERSTORM 3 MIXED PRECIP 0 HEAVY RAIN 0 RAIN 1 LIGHT RAIN 6 FREEZING RAIN 0 LT FREEZING RAIN 0 HAIL 0 HEAVY SNOW 0 SNOW 0 LIGHT SNOW 0 SLEET 0 FOG 5 FOG W/VIS <= 1/4 MILE 1 HAZE 0 - 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 68 DEGREES...AND THE AVERAGE LOW TEMPERATURE IS 39 DEGREES. THE AVERAGE HIGH BY THE END OF THE MONTH IS 52 DEGREES...AND THE AVERAGE LOW TEMPERATURE IS 26 DEGREES. THE AVERAGE MONTHLY PRECIPITATION IS 0.60 INCHES. $$