September weather in Fort Pierre, SD
The average temperature in Fort Pierre in September is 63.6°F (49.7°F–77.5°F). Average precipitation: 1.74 inches.
September is a fall month in Fort Pierre, and is warmer than the annual average of 47°F. Daily temperatures swing about 27.8°F between overnight low and afternoon high. Expect about 6 days with precipitation. Daylight averages about 12h 17m. For travel, September is a comfortable month to visit.
Avg High
77.5°F
Avg Low
49.7°F
Precipitation
1.74 in
Daylight
12h 17m
September records in Fort Pierre
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 106.0°F (1983) | 39.9°F (1965) | 1.25 in (1963) |
| September 2 | 108.0°F (1983) | 39.9°F (1974) | 2.74 in (1999) |
| September 3 | 104.0°F (2005) | 36.0°F (1974) | 0.95 in (1963) |
| September 4 | 105.1°F (1952) | 37.9°F (1962) | 1.70 in (1975) |
| September 5 | 105.1°F (1933) | 37.9°F (1965) | 1.02 in (2004) |
| September 6 | 107.1°F (1976) | 36.0°F (1956) | 1.46 in (1911) |
| September 7 | 100.9°F (1933) | 35.1°F (1986) | 1.60 in (1970) |
| September 8 | 102.0°F (1959) | 37.0°F (2020) | 1.11 in (1900) |
| September 9 | 102.0°F (1994) | 35.1°F (1943) | 1.91 in (2002) |
| September 10 | 104.0°F (1998) | 32.0°F (2020) | 1.11 in (1934) |
| September 11 | 99.0°F (1935) | 33.1°F (1955) | 0.98 in (2019) |
| September 12 | 100.9°F (1939) | 34.0°F (1974) | 0.89 in (1985) |
| September 13 | 99.0°F (1939) | 30.9°F (1949) | 1.13 in (1921) |
| September 14 | 102.0°F (1948) | 30.9°F (1949) | 1.16 in (2025) |
| September 15 | 105.1°F (1948) | 32.0°F (2011) | 1.32 in (2010) |
| September 16 | 98.1°F (2000) | 35.1°F (1959) | 2.03 in (1975) |
| September 17 | 104.0°F (2000) | 34.0°F (1981) | 2.57 in (2025) |
| September 18 | 104.0°F (2000) | 30.0°F (1991) | 1.16 in (1946) |
| September 19 | 100.0°F (1984) | 24.1°F (1991) | 2.45 in (1996) |
| September 20 | 104.0°F (1937) | 33.1°F (1983) | 2.65 in (1989) |
| September 21 | 99.0°F (1937) | 30.9°F (1995) | 0.87 in (1989) |
| September 22 | 99.0°F (1936) | 21.0°F (1995) | 1.01 in (2023) |
| September 23 | 97.0°F (1958) | 28.9°F (1942) | 1.48 in (1977) |
| September 24 | 91.9°F (1990) | 25.0°F (2000) | 0.85 in (1973) |
| September 25 | 96.1°F (1938) | 28.9°F (1942) | 1.19 in (1931) |
| September 26 | 100.0°F (1974) | 24.1°F (1965) | 0.66 in (1966) |
| September 27 | 98.1°F (1952) | 26.1°F (1951) | 0.59 in (2013) |
| September 28 | 95.0°F (2021) | 21.0°F (1951) | 0.41 in (1988) |
| September 29 | 98.1°F (2024) | 28.9°F (1984) | 0.93 in (1965) |
| September 30 | 98.1°F (1980) | 23.0°F (1974) | 1.02 in (1911) |