Fremont County climate

Fremont County Weather in September

NOAA 1991-2020 normals for Riverton, 12.8 km from Fremont County

Average highs run from 81°F on September 1 to 66°F on September 30, and lows from 50°F to 39°F. Normal precipitation for the month is 0.77 in over about 5 wet days.

September day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Fremont County, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
74°F
Average low
44°F
Precipitation
0.77 in
Snowfall
0.6 in
Record high
100°FSep 4, 2022
Record low
21°FSep 27, 1996
Chance of a freeze
59%
Days of 90°F or more
1.3
Daylight
13 h 10 min to 11 h 46 min
Cloud cover
44%
Humidity
42%
Dew point
31°F
Wind
8.1 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
Sep 181°F50°F97°F 202238°F 200816%1%
Sep 280°F49°F96°F 201933°F 200816%1%
Sep 380°F49°F94°F 202237°F 200816%1%
Sep 480°F49°F100°F 202237°F 200816%1%
Sep 579°F48°F97°F 202240°F 200817%1%
Sep 679°F48°F93°F 202236°F 201017%1%
Sep 778°F48°F93°F 202232°F 202017%1%
Sep 878°F47°F91°F 202226°F 202017%1%
Sep 977°F47°F94°F 202124°F 202017%1%
Sep 1077°F47°F90°F 202131°F 200717%1%
Sep 1177°F46°F87°F 200439°F 200318%1%
Sep 1276°F46°F88°F 201737°F 201618%1%
Sep 1376°F46°F90°F 201532°F 199918%1%
Sep 1475°F45°F85°F 201833°F 200318%1%
Sep 1575°F45°F90°F 200037°F 200418%1%
Sep 1674°F44°F93°F 200035°F 200618%2%
Sep 1774°F44°F85°F 200430°F 200619%2%
Sep 1873°F44°F85°F 200428°F 200319%2%
Sep 1973°F43°F90°F 201032°F 199619%2%
Sep 2072°F43°F86°F 201634°F 200019%2%
Sep 2171°F43°F84°F 200130°F 200019%2%
Sep 2271°F42°F86°F 200725°F 200019%2%
Sep 2370°F42°F87°F 201524°F 200019%2%
Sep 2470°F41°F87°F 202024°F 200019%2%
Sep 2569°F41°F90°F 202425°F 200019%3%
Sep 2669°F40°F89°F 201524°F 199619%3%
Sep 2768°F40°F86°F 200121°F 199619%3%
Sep 2868°F39°F86°F 200126°F 199919%3%
Sep 2967°F39°F90°F 202429°F 199919%3%
Sep 3066°F39°F83°F 202330°F 202119%3%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Fremont County, in percent, and of at least 0.1 inch of snowfall.051015201102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (MDT).

September 1
sunrise 6:39 AM, sunset 7:49 PM
September 30
sunrise 7:11 AM, sunset 6:57 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00024061 (Riverton), public domain. Records: NOAA GHCN-Daily, station USW00024061, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.