Climatological Report (Monthly)
Issued by NWS
Issued by NWS
803
CXUS55 KRIW 011731
CLMP60
CLIMATE REPORT
NATIONAL WEATHER SERVICE RIVERTON WY
1107 AM MDT TUE SEP 01 2026
...PRELIMINARY MONTHLY CLIMATE SUMMARY FOR LAKE YELLOWSTONE FOR THE
MONTH OF AUGUST 2026...
...OFFICIAL CLIMATE DATA FOR THE MONTH OF AUGUST 2026 WILL BE
AVAILABLE APPROXIMATELY IN 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
...LAKE YELLOWSTONE WAS WARMER AND WETTER THAN NORMAL IN AUGUST...
THE AVERAGE TEMPERATURE FOR LAKE YELLOWSTONE IN AUGUST WAS 56.6
DEGREES WHICH IS 2.7 DEGREES ABOVE NORMAL. IT WAS THE 5TH WARMEST
AUGUST SINCE RECORDS BEGAN IN 1998. THE WARMEST READING OF THE
MONTH WAS 85 DEGREES ON THE 1ST. THE 7TH HIT 80 DEGREES AND TIED
2003. THE 9TH HIGH OF 80 TIED 2018. THE 21ST HIGH OF 83 BROKE 82
DEGREES FROM 2009. THE COLDEST READING OF THE MONTH WAS 28 DEGREES
ON THE 31ST. THE 5TH LOW OF 34 TIED THE 2012 AND 2016 RECORDS.
TOTAL PRECIPITATION AT LAKE YELLOWSTONE WAS 2.72 INCHES...WHICH WAS
203 PERCENT OF NORMAL. IT WAS THE 6TH WETTEST AUGUST ON RECORD. THE
WETTEST 24-HOUR PERIOD DURING THE MONTH WAS THE 15TH WITH 1.23
INCHES. THIS BROKE THE 2006 RECORD OF 0.31. THE 29TH HAD 0.22 INCHES
AND BROKE 0.13 FROM 2003. THE HIGHEST WIND GUST WAS 44 MPH FROM THE
NORTHWEST ON THE 12TH.
...THE LAKE YELLOWSTONE WY CLIMATE SUMMARY FOR THE MONTH OF AUGUST
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 86 08/01/2000
LOW 25 08/31/2005
HIGHEST 85 08/01
LOWEST 28 08/31
AVG. MAXIMUM 72.6 70.7 1.9
AVG. MINIMUM 40.6 37.0 3.6
MEAN 56.6 53.9 2.7
DAYS MAX >= 90 0
DAYS MAX <= 32 0
DAYS MIN <= 32 2
DAYS MIN <= 0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 4.37 2023
MINIMUM 0.13 2012
TOTALS 2.72 1.34 1.38 1.09
DAILY AVG. 0.09 0.04 0.05
DAYS >= .01 10
DAYS >= .10 7
DAYS >= .50 1
DAYS >= 1.00 1
GREATEST
24 HR. TOTAL 1.23 08/15 TO 08/15
STORM TOTAL 1.23
DEGREE DAYS
HEATING TOTAL 252 346 -94
SINCE 7/1 368 641 -273
COOLING TOTAL 0 0 0
SINCE 1/1 2 0 2
..............................................................
WIND (MPH)
AVERAGE WIND SPEED 2.5
RESULTANT WIND SPEED/DIRECTION 0/290
HIGHEST WIND SPEED/DIRECTION 20/320 DATE 08/12
HIGHEST GUST SPEED/DIRECTION 44/290 DATE 08/12
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.00
NUMBER OF DAYS FAIR 31
NUMBER OF DAYS PC 0
NUMBER OF DAYS CLOUDY 0
AVERAGE RH (PERCENT) 59
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 2 MIXED PRECIP 0
HEAVY RAIN 1 RAIN 0
LIGHT RAIN 10 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.
LOOKING AHEAD TO SEPTEMBER 2026. THE AVERAGE HIGH TEMPERATURE ON THE
FIRST OF THE MONTH IS 67 DEGREES...AND THE AVERAGE LOW TEMPERATURE
IS 33 DEGREES. THE AVERAGE HIGH BY THE END OF THE MONTH IS 53
DEGREES AND THE AVERAGE LOW TEMPERATURE IS 27 DEGREES. THE AVERAGE
MONTHLY PRECIPITATION IS 1.57 INCHES.
$$