Cascade Weather in September
Average highs run from 77°F on September 1 to 67°F on September 30, and lows from 43°F to 36°F. Normal precipitation for the month is 0.99 in over about 6 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
- 73°F
- Average low
- 40°F
- Precipitation
- 0.99 in
- Record high
- 95°FSep 3, 2017
- Record low
- 12°FSep 28, 1999
- Chance of a freeze
- 78%
- Daylight
- 13 h 13 min to 11 h 45 min
- Cloud cover
- 44%
- Humidity
- 44%
- Dew point
- 34°F
- Wind
- 5.8 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.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Sep 1 | 77°F | 43°F | 89°F 2022 | 27°F 2006 | 16% | 0% |
| Sep 2 | 77°F | 43°F | 91°F 2017 | 24°F 2008 | 16% | 0% |
| Sep 3 | 77°F | 43°F | 95°F 2017 | 28°F 2000 | 16% | 0% |
| Sep 4 | 77°F | 43°F | 91°F 1998 | 29°F 1999 | 16% | 0% |
| Sep 5 | 76°F | 42°F | 89°F 2020 | 29°F 1999 | 16% | 0% |
| Sep 6 | 76°F | 42°F | 95°F 2022 | 28°F 2010 | 16% | 0% |
| Sep 7 | 76°F | 42°F | 92°F 2022 | 28°F 2001 | 17% | 0% |
| Sep 8 | 75°F | 42°F | 86°F 2021 | 24°F 2001 | 17% | 0% |
| Sep 9 | 75°F | 41°F | 85°F 2021 | 26°F 2001 | 17% | 0% |
| Sep 10 | 75°F | 41°F | 86°F 2011 | 27°F 2005 | 17% | 0% |
| Sep 11 | 74°F | 41°F | 86°F 2013 | 23°F 2005 | 18% | 0% |
| Sep 12 | 74°F | 41°F | 87°F 2015 | 24°F 2005 | 18% | 0% |
| Sep 13 | 74°F | 40°F | 82°F 2015 | 24°F 2003 | 18% | 0% |
| Sep 14 | 73°F | 40°F | 84°F 2000 | 25°F 2005 | 19% | 0% |
| Sep 15 | 73°F | 40°F | 80°F 1998 | 25°F 2006 | 19% | |
| Sep 16 | 73°F | 40°F | 83°F 2008 | 27°F 2017 | 19% | |
| Sep 17 | 72°F | 39°F | 84°F 2020 | 25°F 2003 | 19% | |
| Sep 18 | 72°F | 39°F | 80°F 2009 | 23°F 2003 | 20% | |
| Sep 19 | 72°F | 39°F | 81°F 2025 | 26°F 2005 | 20% | |
| Sep 20 | 71°F | 39°F | 81°F 2025 | 27°F 2001 | 20% | |
| Sep 21 | 71°F | 38°F | 78°F 2012 | 25°F 2004 | 21% | |
| Sep 22 | 70°F | 38°F | 81°F 2009 | 25°F 2005 | 21% | |
| Sep 23 | 70°F | 38°F | 83°F 2009 | 24°F 2006 | 21% | |
| Sep 24 | 69°F | 37°F | 86°F 2009 | 18°F 2000 | 21% | |
| Sep 25 | 69°F | 37°F | 84°F 2009 | 21°F 2000 | 22% | |
| Sep 26 | 69°F | 37°F | 82°F 2022 | 23°F 2000 | 22% | |
| Sep 27 | 68°F | 37°F | 85°F 2022 | 18°F 1999 | 22% | |
| Sep 28 | 68°F | 36°F | 82°F 2010 | 12°F 1999 | 23% | |
| Sep 29 | 67°F | 36°F | 80°F 2011 | 17°F 1999 | 23% | |
| Sep 30 | 67°F | 36°F | 82°F 2010 | 22°F 2007 | 23% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MDT).
- September 1
- sunrise 7:07 AM, sunset 8:20 PM
- September 30
- sunrise 7:41 AM, sunset 7:26 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00101514 (Cascade 1 Nw), public domain. Records: NOAA GHCN-Daily, station USW00094182, 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.