Duluth Weather in September
Average highs run from 72°F on September 1 to 61°F on September 30, and lows from 55°F to 45°F. Normal precipitation for the month is 3.39 in over about 10 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
- 67°F
- Average low
- 50°F
- Precipitation
- 3.39 in
- Record high
- 97°FSep 8, 1976
- Record low
- 19°FSep 13, 1963
- Chance of a freeze
- 23%
- Daylight
- 13 h 20 min to 11 h 44 min
- Cloud cover
- 66%
- Humidity
- 76%
- Dew point
- 49°F
- Wind
- 9.4 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 | 72°F | 55°F | 92°F 1953 | 32°F 1909 | 32% | 0% |
| Sep 2 | 71°F | 55°F | 94°F 1983 | 37°F 1965 | 33% | 0% |
| Sep 3 | 71°F | 54°F | 94°F 1947 | 33°F 1974 | 33% | 0% |
| Sep 4 | 71°F | 54°F | 91°F 1948 | 30°F 1961 | 33% | 0% |
| Sep 5 | 70°F | 54°F | 94°F 1947 | 33°F 1957 | 33% | 0% |
| Sep 6 | 70°F | 53°F | 93°F 1978 | 35°F 1965 | 33% | 0% |
| Sep 7 | 70°F | 53°F | 91°F 2002 | 32°F 1956 | 33% | 0% |
| Sep 8 | 70°F | 53°F | 97°F 1976 | 28°F 1956 | 33% | 0% |
| Sep 9 | 69°F | 52°F | 89°F 1947 | 29°F 1956 | 33% | 0% |
| Sep 10 | 69°F | 52°F | 89°F 1947 | 30°F 1917 | 33% | 0% |
| Sep 11 | 69°F | 52°F | 90°F 2005 | 28°F 1965 | 33% | 0% |
| Sep 12 | 68°F | 52°F | 93°F 1948 | 28°F 1955 | 33% | 0% |
| Sep 13 | 68°F | 51°F | 87°F 1990 | 19°F 1963 | 33% | 0% |
| Sep 14 | 68°F | 51°F | 81°F 1997 | 29°F 1963 | 33% | 0% |
| Sep 15 | 67°F | 50°F | 86°F 1920 | 30°F 2007 | 32% | 0% |
| Sep 16 | 67°F | 50°F | 93°F 1948 | 32°F 1916 | 32% | 0% |
| Sep 17 | 66°F | 50°F | 90°F 1948 | 25°F 1959 | 32% | 0% |
| Sep 18 | 66°F | 49°F | 88°F 1984 | 29°F 1916 | 32% | 0% |
| Sep 19 | 66°F | 49°F | 90°F 1984 | 28°F 1929 | 33% | 0% |
| Sep 20 | 65°F | 49°F | 85°F 2022 | 25°F 1956 | 33% | 0% |
| Sep 21 | 65°F | 48°F | 87°F 1941 | 26°F 1956 | 32% | 0% |
| Sep 22 | 64°F | 48°F | 83°F 1941 | 25°F 1974 | 32% | 0% |
| Sep 23 | 64°F | 48°F | 87°F 2017 | 28°F 1913 | 32% | 0% |
| Sep 24 | 63°F | 47°F | 85°F 1930 | 24°F 1913 | 32% | 0% |
| Sep 25 | 63°F | 47°F | 84°F 1950 | 23°F 1947 | 32% | 0% |
| Sep 26 | 63°F | 46°F | 90°F 1920 | 23°F 1965 | 32% | 0% |
| Sep 27 | 62°F | 46°F | 86°F 2024 | 22°F 1957 | 32% | 0% |
| Sep 28 | 62°F | 46°F | 82°F 1952 | 23°F 1961 | 32% | 0% |
| Sep 29 | 61°F | 45°F | 81°F 2000 | 25°F 1962 | 32% | 0% |
| Sep 30 | 61°F | 45°F | 83°F 1952 | 22°F 1947 | 32% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 6:28 AM, sunset 7:48 PM
- September 30
- sunrise 7:06 AM, sunset 6:50 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00478349 (Superior), public domain. Records: NOAA GHCN-Daily, station USC00478349, 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.