Mahnomen Weather in September
Average highs run from 74°F on September 1 to 64°F on September 30, and lows from 51°F to 42°F. Normal precipitation for the month is 2.76 in.
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
- 69°F
- Average low
- 47°F
- Precipitation
- 2.76 in
- Record high
- 98°FSep 6, 1978
- Record low
- 14°FSep 17, 1929
- Chance of a freeze
- 59%
- Daylight
- 13 h 21 min to 11 h 43 min
- Cloud cover
- 59%
- Humidity
- 67%
- Dew point
- 46°F
- Wind
- 11.2 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 | 74°F | 51°F | 90°F 1929 | 31°F 1931 | |
| Sep 2 | 74°F | 51°F | 95°F 1983 | 32°F 1930 | |
| Sep 3 | 73°F | 50°F | 94°F 1976 | 33°F 1974 | |
| Sep 4 | 73°F | 50°F | 94°F 1978 | 30°F 1929 | |
| Sep 5 | 73°F | 50°F | 96°F 1978 | 32°F 1929 | |
| Sep 6 | 72°F | 50°F | 98°F 1978 | 32°F 1932 | |
| Sep 7 | 72°F | 49°F | 96°F 1931 | 31°F 1979 | |
| Sep 8 | 72°F | 49°F | 98°F 1931 | 27°F 2012 | |
| Sep 9 | 71°F | 49°F | 92°F 1931 | 21°F 2012 | |
| Sep 10 | 71°F | 48°F | 94°F 1931 | 18°F 2012 | |
| Sep 11 | 71°F | 48°F | 95°F 1931 | 29°F 1964 | |
| Sep 12 | 71°F | 48°F | 89°F 1976 | 30°F 2012 | |
| Sep 13 | 70°F | 48°F | 88°F 1927 | 27°F 1970 | |
| Sep 14 | 70°F | 47°F | 86°F 2025 | 30°F 2011 | |
| Sep 15 | 70°F | 47°F | 84°F 1927 | 28°F 1984 | |
| Sep 16 | 69°F | 47°F | 87°F 1979 | 25°F 2012 | |
| Sep 17 | 69°F | 46°F | 89°F 1998 | 14°F 1929 | |
| Sep 18 | 69°F | 46°F | 90°F 1998 | 22°F 1929 | |
| Sep 19 | 68°F | 46°F | 90°F 1970 | 30°F 1962 | |
| Sep 20 | 68°F | 45°F | 92°F 1984 | 23°F 1932 | |
| Sep 21 | 68°F | 45°F | 86°F 2019 | 25°F 1995 | |
| Sep 22 | 67°F | 45°F | 85°F 2017 | 21°F 1974 | |
| Sep 23 | 67°F | 44°F | 85°F 1930 | 21°F 1976 | |
| Sep 24 | 67°F | 44°F | 86°F 1990 | 26°F 1989 | |
| Sep 25 | 66°F | 44°F | 86°F 1990 | 21°F 1928 | |
| Sep 26 | 66°F | 43°F | 88°F 1974 | 20°F 1965 | |
| Sep 27 | 65°F | 43°F | 86°F 1974 | 20°F 1930 | |
| Sep 28 | 65°F | 43°F | 84°F 1995 | 16°F 1930 | |
| Sep 29 | 64°F | 42°F | 91°F 2025 | 22°F 1930 | |
| Sep 30 | 64°F | 42°F | 87°F 1989 | 25°F 1974 |
Chance of rain
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 6:43 AM, sunset 8:04 PM
- September 30
- sunrise 7:22 AM, sunset 7:05 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00215012 (Mahnomen), public domain. Records: NOAA GHCN-Daily, station USC00215012, 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.