Custer County Weather in September
Average highs run from 80°F on September 1 to 68°F on September 30, and lows from 46°F to 38°F. Normal precipitation for the month is 0.85 in over about 5 wet days.
September day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
September at a glance
- Average high
- 75°F
- Average low
- 42°F
- Precipitation
- 0.85 in
- Record high
- 99°FSep 3, 2022
- Record low
- 19°FSep 28, 1999
- Chance of a freeze
- 72%
- Days of 90°F or more
- 0.8
- Daylight
- 13 h 13 min to 11 h 45 min
- Cloud cover
- 43%
- Humidity
- 50%
- Dew point
- 27°F
- Wind
- 5.1 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation.
| Date | Normal high | Normal low | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| Sep 1 | 80°F | 46°F | 95°F 2019 | 35°F 2006 | 15% |
| Sep 2 | 80°F | 46°F | 93°F 2007 | 30°F 2008 | 15% |
| Sep 3 | 80°F | 46°F | 99°F 2022 | 35°F 2004 | 15% |
| Sep 4 | 79°F | 45°F | 97°F 2022 | 34°F 2004 | 15% |
| Sep 5 | 79°F | 45°F | 98°F 2020 | 34°F 2008 | 15% |
| Sep 6 | 79°F | 45°F | 99°F 2022 | 29°F 2010 | 15% |
| Sep 7 | 78°F | 45°F | 97°F 2022 | 34°F 2010 | 15% |
| Sep 8 | 78°F | 44°F | 96°F 2021 | 32°F 2001 | 16% |
| Sep 9 | 77°F | 44°F | 94°F 2021 | 32°F 2020 | 16% |
| Sep 10 | 77°F | 44°F | 86°F 2024 | 32°F 2007 | 16% |
| Sep 11 | 77°F | 43°F | 88°F 2015 | 28°F 2005 | 16% |
| Sep 12 | 76°F | 43°F | 89°F 2015 | 28°F 2014 | 16% |
| Sep 13 | 76°F | 43°F | 89°F 2015 | 27°F 2016 | 16% |
| Sep 14 | 75°F | 43°F | 89°F 2000 | 32°F 2003 | 16% |
| Sep 15 | 75°F | 42°F | 91°F 2000 | 33°F 2026 | 16% |
| Sep 16 | 75°F | 42°F | 88°F 2000 | 33°F 2006 | 16% |
| Sep 17 | 74°F | 42°F | 84°F 2009 | 27°F 2006 | 16% |
| Sep 18 | 74°F | 41°F | 86°F 2009 | 27°F 2003 | 16% |
| Sep 19 | 73°F | 41°F | 89°F 2009 | 31°F 2013 | 17% |
| Sep 20 | 73°F | 41°F | 83°F 2014 | 33°F 2003 | 17% |
| Sep 21 | 72°F | 41°F | 82°F 1999 | 30°F 2004 | 17% |
| Sep 22 | 72°F | 40°F | 84°F 2015 | 30°F 2002 | 17% |
| Sep 23 | 71°F | 40°F | 86°F 2009 | 28°F 2000 | 17% |
| Sep 24 | 71°F | 40°F | 87°F 2009 | 23°F 2000 | 17% |
| Sep 25 | 70°F | 39°F | 89°F 2024 | 27°F 2018 | 17% |
| Sep 26 | 70°F | 39°F | 87°F 2021 | 30°F 2000 | 17% |
| Sep 27 | 69°F | 39°F | 85°F 2021 | 25°F 1999 | 17% |
| Sep 28 | 69°F | 38°F | 89°F 2024 | 19°F 1999 | 17% |
| Sep 29 | 68°F | 38°F | 83°F 2024 | 25°F 1999 | 17% |
| Sep 30 | 68°F | 38°F | 86°F 2011 | 24°F 2007 | 17% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (MDT).
- September 1
- sunrise 7:00 AM, sunset 8:13 PM
- September 30
- sunrise 7:34 AM, sunset 7:19 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00004114 (Challis AP), public domain. Records: NOAA GHCN-Daily, station USW00004114, 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.