157
CXUS55 KRIW 011715
CLMGEY
CLIMATE REPORT
NATIONAL WEATHER SERVICE RIVERTON WY
1105 AM MDT THU OCT 01 2026
...PRELIMINARY MONTHLY CLIMATE SUMMARY FOR GREYBULL FOR THE MONTH OF
SEPTEMBER 2026...
...OFFICIAL CLIMATE DATA FOR THE MONTH OF SEPTEMBER 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
..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 FIFTH WARMEST
SEPTEMBER ON RECORD. THE WARMEST TEMPERATURE FOR THE MONTH WAS 93
DEGREES ON THE 4TH. THE COLDEST TEMPERATURE WAS 40 DEGREES ON THE
15TH AND 30TH. NO TEMPERATURE RECORDS WERE BROKEN THIS MONTH.
PRECIPITATION FOR THE MONTH WAS 0.17 INCHES...WHICH IS 20 PERCENT OF
NORMAL. IT WAS THE 5TH DRIEST SEPTEMBER ON RECORD. THE WETTEST 24-
HOUR PERIOD HAD 0.12 INCHES ON THE 20TH. NO PRECIPITATION RECORDS
WERE BROKEN THIS MONTH. THE HIGHEST WIND GUST WAS 47 MPH. IT
OCCURRED ON THE 2ND FROM THE SOUTHEAST.
..THE GREYBULL 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 103 09/04/2022
LOW 27 09/18/2003
09/29/1999
HIGHEST 93 09/04
LOWEST 40 09/15
09/30
AVG. MAXIMUM 80.7 76.7 4.0
AVG. MINIMUM 48.1 45.1 3.0
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 0.17 0.83 -0.66 0.65
DAILY AVG. 0.01 0.03 -0.02
DAYS >= .01 4
DAYS >= .10 1
DAYS >= .50 0
DAYS >= 1.00 0
GREATEST
24 HR. TOTAL 0.12 09/20 TO 09/20
STORM TOTAL 0.12
DEGREE DAYS
HEATING TOTAL 70 169 -99
SINCE 7/1 72 189 -117
COOLING TOTAL 57 46 11
SINCE 1/1 855 742 113
..........................................................
WIND (MPH)
AVERAGE WIND SPEED 6.3
RESULTANT WIND SPEED/DIRECTION 2/310
HIGHEST WIND SPEED/DIRECTION 33/320 DATE 09/11
HIGHEST GUST SPEED/DIRECTION 47/150 DATE 09/02
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.13
NUMBER OF DAYS FAIR 28
NUMBER OF DAYS PC 1
NUMBER OF DAYS CLOUDY 1
AVERAGE RH (PERCENT) 47
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 1 MIXED PRECIP 0
HEAVY RAIN 0 RAIN 1
LIGHT RAIN 9 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 0 SLEET 0
FOG 2 FOG W/VIS <= 1/4 MILE 1
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 2026. THE AVERAGE HIGH TEMPERATURE ON THE
FIRST OF THE MONTH IS 68 DEGREES...AND THE AVERAGE LOW TEMPERATURE
IS 9 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.
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