Climatological Report (Monthly)
Issued by NWS
Issued by NWS
270
CXUS55 KRIW 012012
CLMP60
CLIMATE REPORT
NATIONAL WEATHER SERVICE RIVERTON WY
212 PM MDT WED OCT 01 2025
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...THE LAKE YELLOWSTONE 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 83 09/07/2022
LOW 13 09/24/2000
HIGHEST 78 09/03
LOWEST 27 09/23
AVG. MAXIMUM 64.6 60.5 4.1
AVG. MINIMUM 32.5 30.3 2.2
MEAN 48.5 45.4 3.1
DAYS MAX >= 90 0
DAYS MAX <= 32 0
DAYS MIN <= 32 16
DAYS MIN <= 0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 4.09 2013
MINIMUM 0.21 2018
TOTALS 1.46 1.57 -0.11 1.43
DAILY AVG. 0.05 0.05 -0.00
DAYS >= .01 11
DAYS >= .10 3
DAYS >= .50 1
DAYS >= 1.00 0
GREATEST
24 HR. TOTAL 0.76 09/07 TO 09/07
STORM TOTAL 0.76
DEGREE DAYS
HEATING TOTAL 484 588 -104
SINCE 7/1 1000 1230 -230
COOLING TOTAL 0 0 0
SINCE 1/1 1 0 1
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WIND (MPH)
AVERAGE WIND SPEED 1.9
RESULTANT WIND SPEED/DIRECTION 0/080
HIGHEST WIND SPEED/DIRECTION 17/270 DATE 09/07
17/280 09/11
HIGHEST GUST SPEED/DIRECTION 30/270 DATE 09/07
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.00
NUMBER OF DAYS FAIR 28
NUMBER OF DAYS PC 0
NUMBER OF DAYS CLOUDY 0
AVERAGE RH (PERCENT) 63
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 1 MIXED PRECIP 0
HEAVY RAIN 1 RAIN 1
LIGHT RAIN 11 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 0 SLEET 0
FOG 0 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.
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