September weather in Vandalia, IL
The average temperature in Vandalia in September is 67.7°F (55.8°F–79.6°F). Average precipitation: 3.07 inches.
September is a fall month in Vandalia, and is warmer than the annual average of 54.2°F. Daily temperatures swing about 23.8°F between overnight low and afternoon high. Expect about 7 days with precipitation. Daylight averages about 12h 14m. For travel, September is one of the best months of the year to visit.
Avg High
79.6°F
Avg Low
55.8°F
Precipitation
3.07 in
Daylight
12h 14m
September records in Vandalia
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 96.1°F (1980) | 46.9°F (1987) | 3.74 in (2012) |
| September 2 | 98.1°F (2011) | 42.1°F (1901) | 1.91 in (2003) |
| September 3 | 97.0°F (2011) | 46.9°F (1974) | 3.42 in (1993) |
| September 4 | 96.1°F (2011) | 44.1°F (1974) | 1.15 in (1991) |
| September 5 | 96.1°F (2007) | 39.9°F (1997) | 1.60 in (2008) |
| September 6 | 96.1°F (1990) | 48.0°F (1988) | 1.41 in (2009) |
| September 7 | 98.1°F (1901) | 48.9°F (1975) | 0.40 in (2007) |
| September 8 | 95.0°F (1901) | 39.9°F (1986) | 1.58 in (2012) |
| September 9 | 98.1°F (1901) | 42.1°F (1986) | 1.65 in (1984) |
| September 10 | 98.1°F (1983) | 42.1°F (1902) | 1.65 in (1973) |
| September 11 | 97.0°F (1983) | 46.0°F (1993) | 1.27 in (1984) |
| September 12 | 90.0°F (1903) | 46.9°F (1976) | 1.86 in (1949) |
| September 13 | 91.9°F (1980) | 33.1°F (1902) | 3.44 in (1933) |
| September 14 | 95.0°F (1991) | 32.0°F (1902) | 1.40 in (1984) |
| September 15 | 98.1°F (1903) | 35.1°F (1902) | 1.32 in (2008) |
| September 16 | 93.9°F (1991) | 39.0°F (1979) | 1.30 in (1939) |
| September 17 | 90.0°F (1997) | 34.0°F (1900) | 1.65 in (1980) |
| September 18 | 90.0°F (1978) | 28.9°F (1901) | 0.95 in (1982) |
| September 19 | 95.0°F (1983) | 28.0°F (1901) | 1.23 in (1900) |
| September 20 | 93.0°F (1978) | 35.1°F (1991) | 1.28 in (2005) |
| September 21 | 91.0°F (1978) | 36.0°F (1991) | 1.86 in (1945) |
| September 22 | 91.9°F (1980) | 35.1°F (1983) | 1.02 in (1990) |
| September 23 | 93.0°F (2005) | 30.0°F (1974) | 2.50 in (1993) |
| September 24 | 95.0°F (2007) | 33.1°F (1974) | 1.61 in (2025) |
| September 25 | 91.0°F (1901) | 34.0°F (1995) | 2.75 in (1998) |
| September 26 | 90.0°F (1986) | 36.0°F (1984) | 1.83 in (2012) |
| September 27 | 90.0°F (1986) | 28.0°F (1899) | 1.58 in (1904) |
| September 28 | 91.9°F (1904) | 35.1°F (1899) | 3.02 in (1936) |
| September 29 | 91.0°F (1986) | 32.0°F (1899) | 1.28 in (2005) |
| September 30 | 88.0°F (1986) | 19.9°F (1899) | 0.79 in (1945) |