Thompson Falls Weather in September
Average highs run from 81°F on September 1 to 68°F on September 30, and lows from 48°F to 40°F. Normal precipitation for the month is 0.97 in over about 8 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
- 44°F
- Precipitation
- 0.97 in
- Record high
- 85°FSep 3, 1950
- Record low
- 17°FSep 22, 2000
- Chance of a freeze
- 36%
- Days of 90°F or more
- 3.7
- Daylight
- 13 h 21 min to 11 h 43 min
- Cloud cover
- 51%
- Humidity
- 58%
- Dew point
- 37°F
- Wind
- 4.3 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 | 81°F | 48°F | 82°F 1945 | 34°F 1999 | 22% | 0% |
| Sep 2 | 81°F | 48°F | 83°F 2022 | 33°F 2004 | 22% | 0% |
| Sep 3 | 80°F | 48°F | 85°F 1950 | 33°F 2000 | 23% | 0% |
| Sep 4 | 80°F | 47°F | 82°F 1955 | 33°F 2014 | 23% | 0% |
| Sep 5 | 80°F | 47°F | 82°F 2006 | 32°F 1996 | 23% | 0% |
| Sep 6 | 79°F | 47°F | 83°F 2024 | 33°F 2010 | 24% | 0% |
| Sep 7 | 79°F | 47°F | 82°F 2024 | 30°F 2020 | 24% | 0% |
| Sep 8 | 79°F | 46°F | 80°F 2024 | 29°F 2020 | 24% | 0% |
| Sep 9 | 78°F | 46°F | 77°F 2011 | 30°F 2000 | 25% | 0% |
| Sep 10 | 78°F | 46°F | 77°F 2011 | 28°F 2014 | 25% | 0% |
| Sep 11 | 78°F | 46°F | 83°F 1953 | 24°F 1949 | 25% | 0% |
| Sep 12 | 77°F | 45°F | 76°F 2011 | 24°F 1949 | 25% | 0% |
| Sep 13 | 77°F | 45°F | 77°F 1944 | 30°F 2016 | 26% | 0% |
| Sep 14 | 76°F | 45°F | 74°F 2002 | 30°F 1941 | 26% | 0% |
| Sep 15 | 76°F | 45°F | 77°F 1998 | 30°F 1941 | 27% | 0% |
| Sep 16 | 76°F | 44°F | 79°F 1938 | 29°F 1947 | 27% | 0% |
| Sep 17 | 75°F | 44°F | 78°F 1938 | 24°F 1947 | 27% | 0% |
| Sep 18 | 75°F | 44°F | 78°F 1938 | 23°F 1957 | 28% | 0% |
| Sep 19 | 74°F | 43°F | 72°F 2008 | 25°F 1957 | 28% | 0% |
| Sep 20 | 74°F | 43°F | 71°F 1938 | 29°F 1941 | 28% | 0% |
| Sep 21 | 73°F | 43°F | 77°F 1938 | 19°F 2000 | 29% | 0% |
| Sep 22 | 73°F | 43°F | 72°F 1952 | 17°F 2000 | 29% | 0% |
| Sep 23 | 72°F | 42°F | 78°F 2009 | 19°F 2000 | 29% | 0% |
| Sep 24 | 72°F | 42°F | 77°F 2011 | 26°F 1948 | 30% | 0% |
| Sep 25 | 71°F | 42°F | 78°F 1952 | 29°F 1955 | 30% | 0% |
| Sep 26 | 71°F | 42°F | 74°F 1952 | 26°F 1999 | 31% | 0% |
| Sep 27 | 70°F | 41°F | 72°F 2022 | 25°F 1945 | 31% | 0% |
| Sep 28 | 70°F | 41°F | 74°F 2022 | 20°F 2019 | 32% | 0% |
| Sep 29 | 69°F | 41°F | 70°F 2016 | 20°F 2019 | 32% | 0% |
| Sep 30 | 68°F | 40°F | 74°F 1957 | 21°F 1950 | 33% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MDT).
- September 1
- sunrise 7:00 AM, sunset 8:21 PM
- September 30
- sunrise 7:39 AM, sunset 7:22 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00248211 (Thompson Falls Ph), public domain. Records: NOAA GHCN-Daily, station USW00024154, 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 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.