September weather in Grand Marais, MN
The average temperature in Grand Marais in September is 54.6°F (47.3°F–61.9°F). Average precipitation: 2.83 inches.
September is a fall month in Grand Marais, and is warmer than the annual average of 38.3°F. Daily temperatures swing about 14.6°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 12h 20m. For travel, September is a comfortable month to visit.
Avg High
61.9°F
Avg Low
47.3°F
Precipitation
2.83 in
Daylight
12h 20m
September records in Grand Marais
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 90.0°F (1929) | 34.0°F (1974) | 2.37 in (1973) |
| September 2 | 89.1°F (1929) | 37.0°F (1946) | 1.47 in (1992) |
| September 3 | 84.0°F (1978) | 39.0°F (1924) | 1.51 in (1985) |
| September 4 | 84.0°F (1990) | 37.9°F (2010) | 2.25 in (1989) |
| September 5 | 82.9°F (2006) | 35.1°F (2010) | 1.69 in (1946) |
| September 6 | 87.1°F (1998) | 36.0°F (1986) | 1.45 in (2023) |
| September 7 | 82.9°F (1913) | 36.0°F (1944) | 2.00 in (1933) |
| September 8 | 79.0°F (1963) | 37.0°F (1993) | 1.73 in (1921) |
| September 9 | 82.0°F (2011) | 30.0°F (1917) | 1.61 in (1991) |
| September 10 | 77.0°F (1916) | 35.1°F (1924) | 3.49 in (1961) |
| September 11 | 88.0°F (2011) | 35.1°F (1918) | 1.37 in (2010) |
| September 12 | 87.1°F (2011) | 32.0°F (2007) | 1.10 in (1951) |
| September 13 | 78.1°F (1948) | 30.9°F (1953) | 2.00 in (1914) |
| September 14 | 77.0°F (1920) | 30.9°F (2011) | 2.28 in (1941) |
| September 15 | 73.9°F (1920) | 28.9°F (2007) | 0.89 in (2017) |
| September 16 | 75.9°F (1994) | 28.9°F (2011) | 1.16 in (1995) |
| September 17 | 84.9°F (1925) | 32.0°F (2011) | 1.07 in (1950) |
| September 18 | 82.9°F (1984) | 34.0°F (1929) | 1.71 in (2015) |
| September 19 | 82.9°F (1984) | 32.0°F (2012) | 2.00 in (1925) |
| September 20 | 82.9°F (1922) | 27.0°F (1956) | 2.45 in (1972) |
| September 21 | 81.0°F (1940) | 30.9°F (1999) | 2.61 in (1970) |
| September 22 | 77.0°F (1936) | 28.9°F (1942) | 2.00 in (1924) |
| September 23 | 78.1°F (1922) | 28.9°F (1974) | 0.90 in (1914) |
| September 24 | 77.0°F (2007) | 32.0°F (2000) | 2.74 in (1977) |
| September 25 | 73.9°F (1979) | 25.0°F (1942) | 1.32 in (1959) |
| September 26 | 75.9°F (2025) | 26.1°F (1965) | 1.00 in (1981) |
| September 27 | 75.0°F (1918) | 28.0°F (1935) | 1.04 in (1946) |
| September 28 | 75.0°F (1914) | 23.0°F (1942) | 0.46 in (1963) |
| September 29 | 77.0°F (1989) | 28.0°F (1945) | 0.65 in (1983) |
| September 30 | 72.0°F (1957) | 27.0°F (1920) | 1.98 in (1965) |