September weather in Mill Creek, IL
The average temperature in Mill Creek in September is 71.3°F (59.2°F–83.5°F). Average precipitation: 3.49 inches.
September is a fall month in Mill Creek, and is warmer than the annual average of 58.5°F. Daily temperatures swing about 24.3°F between overnight low and afternoon high. Expect about 7 days with precipitation. Daylight averages about 12h 14m. For travel, September is a comfortable month to visit.
Avg High
83.5°F
Avg Low
59.2°F
Precipitation
3.49 in
Daylight
12h 14m
September records in Mill Creek
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 102.0°F (1913) | 46.0°F (1967) | 2.44 in (1982) |
| September 2 | 104.0°F (1913) | 45.0°F (1949) | 2.24 in (2020) |
| September 3 | 104.0°F (1913) | 46.9°F (1952) | 3.35 in (1904) |
| September 4 | 102.9°F (1925) | 46.0°F (1952) | 1.41 in (1918) |
| September 5 | 105.1°F (1925) | 44.1°F (1997) | 2.37 in (1948) |
| September 6 | 107.1°F (1925) | 46.0°F (1988) | 1.62 in (2009) |
| September 7 | 104.0°F (1925) | 44.1°F (1988) | 3.15 in (1909) |
| September 8 | 102.0°F (1900) | 46.9°F (1898) | 1.95 in (1916) |
| September 9 | 102.9°F (1925) | 45.0°F (2024) | 1.18 in (1950) |
| September 10 | 100.9°F (1912) | 45.0°F (1924) | 2.12 in (1909) |
| September 11 | 100.9°F (1897) | 39.9°F (1917) | 4.04 in (1965) |
| September 12 | 99.0°F (1897) | 43.0°F (1940) | 3.45 in (1913) |
| September 13 | 99.0°F (1980) | 37.0°F (1902) | 2.95 in (1934) |
| September 14 | 97.0°F (1896) | 37.9°F (1902) | 1.62 in (1989) |
| September 15 | 97.0°F (1897) | 39.9°F (1902) | 1.61 in (1930) |
| September 16 | 100.9°F (1897) | 43.0°F (1966) | 2.25 in (1996) |
| September 17 | 98.1°F (1896) | 41.0°F (1901) | 1.80 in (1905) |
| September 18 | 98.1°F (1953) | 37.0°F (1901) | 2.05 in (1986) |
| September 19 | 97.0°F (1925) | 37.0°F (1901) | 2.30 in (1904) |
| September 20 | 98.1°F (1908) | 37.9°F (1896) | 3.48 in (1954) |
| September 21 | 97.0°F (1908) | 36.0°F (1927) | 2.97 in (1909) |
| September 22 | 97.0°F (2022) | 37.0°F (1983) | 1.40 in (1925) |
| September 23 | 93.0°F (1931) | 32.0°F (1995) | 4.45 in (1993) |
| September 24 | 93.0°F (1935) | 32.0°F (1995) | 1.80 in (1940) |
| September 25 | 93.9°F (1900) | 35.1°F (1950) | 3.75 in (1937) |
| September 26 | 97.0°F (1900) | 36.0°F (2001) | 1.71 in (2011) |
| September 27 | 93.0°F (1911) | 37.0°F (1942) | 1.59 in (1925) |
| September 28 | 95.0°F (1953) | 33.1°F (1942) | 2.30 in (1906) |
| September 29 | 99.0°F (1953) | 37.9°F (1899) | 1.55 in (1934) |
| September 30 | 93.0°F (1998) | 32.0°F (1899) | 2.30 in (1965) |