September weather in Reliance, SD
The average temperature in Reliance in September is 64.9°F (49.5°F–80.3°F). Average precipitation: 1.72 inches.
September is a fall month in Reliance, and is warmer than the annual average of 48.1°F. Daily temperatures swing about 30.8°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
80.3°F
Avg Low
49.5°F
Precipitation
1.72 in
Daylight
12h 17m
September records in Reliance
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 106.0°F (1983) | 35.1°F (1965) | 0.96 in (1963) |
| September 2 | 108.0°F (1983) | 39.0°F (1952) | 3.51 in (2021) |
| September 3 | 105.1°F (1983) | 30.9°F (1974) | 1.30 in (1963) |
| September 4 | 106.0°F (1933) | 23.0°F (2008) | 1.00 in (1949) |
| September 5 | 109.0°F (1933) | 34.0°F (1935) | 0.96 in (2004) |
| September 6 | 107.1°F (1976) | 32.0°F (1956) | 1.72 in (1948) |
| September 7 | 104.0°F (1933) | 32.0°F (1895) | 2.18 in (1938) |
| September 8 | 105.1°F (1931) | 36.0°F (1995) | 1.33 in (2015) |
| September 9 | 109.9°F (1904) | 30.9°F (1943) | 1.90 in (2002) |
| September 10 | 106.0°F (1931) | 28.0°F (1922) | 1.08 in (1934) |
| September 11 | 102.0°F (1931) | 23.0°F (1955) | 1.51 in (1906) |
| September 12 | 102.0°F (1939) | 25.0°F (1902) | 1.72 in (2019) |
| September 13 | 100.0°F (1939) | 28.0°F (1949) | 1.24 in (1938) |
| September 14 | 102.0°F (1939) | 28.0°F (1904) | 1.15 in (1991) |
| September 15 | 105.1°F (1955) | 28.0°F (1961) | 1.20 in (1924) |
| September 16 | 102.0°F (1910) | 27.0°F (1903) | 1.36 in (1965) |
| September 17 | 100.9°F (1955) | 24.1°F (1903) | 1.02 in (2025) |
| September 18 | 99.0°F (1908) | 27.0°F (1901) | 1.15 in (1946) |
| September 19 | 102.0°F (1984) | 19.9°F (1896) | 1.91 in (1996) |
| September 20 | 102.9°F (1937) | 21.0°F (1918) | 2.10 in (1950) |
| September 21 | 100.9°F (1937) | 28.0°F (1934) | 2.00 in (1989) |
| September 22 | 102.0°F (1922) | 21.9°F (1995) | 1.34 in (1910) |
| September 23 | 102.9°F (1935) | 28.0°F (1989) | 2.47 in (2023) |
| September 24 | 96.1°F (1901) | 19.0°F (1893) | 0.90 in (1931) |
| September 25 | 95.0°F (1905) | 10.9°F (1926) | 0.85 in (1915) |
| September 26 | 100.9°F (1974) | 10.9°F (1926) | 1.15 in (1929) |
| September 27 | 100.9°F (1956) | 21.0°F (1928) | 0.42 in (2006) |
| September 28 | 99.0°F (1905) | 19.9°F (1951) | 0.90 in (2013) |
| September 29 | 97.0°F (2024) | 21.0°F (1984) | 1.04 in (1973) |
| September 30 | 97.0°F (1989) | 19.9°F (1984) | 1.44 in (1907) |