September weather in Walnut, IL
The average temperature in Walnut in September is 64.4°F (52.9°F–76.0°F). Average precipitation: 3.40 inches.
September is a fall month in Walnut, and is warmer than the annual average of 49.3°F. Daily temperatures swing about 23.1°F between overnight low and afternoon high. Expect about 6 days with precipitation. Daylight averages about 12h 16m. For travel, September is one of the best months of the year to visit.
Avg High
76.0°F
Avg Low
52.9°F
Precipitation
3.40 in
Daylight
12h 16m
September records in Walnut
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 100.9°F (1953) | 39.0°F (1967) | 4.08 in (1926) |
| September 2 | 100.9°F (1913) | 39.9°F (1946) | 2.06 in (1897) |
| September 3 | 100.0°F (1913) | 39.9°F (1974) | 1.76 in (1926) |
| September 4 | 98.1°F (1925) | 37.9°F (1974) | 2.32 in (1962) |
| September 5 | 100.9°F (1899) | 39.9°F (1988) | 2.58 in (1989) |
| September 6 | 98.1°F (1922) | 37.9°F (1988) | 1.68 in (1944) |
| September 7 | 99.0°F (1893) | 37.9°F (1986) | 1.12 in (1907) |
| September 8 | 99.0°F (1897) | 37.9°F (1986) | 1.62 in (1925) |
| September 9 | 99.0°F (1897) | 41.0°F (1924) | 2.78 in (1941) |
| September 10 | 99.0°F (1897) | 39.9°F (1917) | 3.36 in (1992) |
| September 11 | 96.1°F (1897) | 36.0°F (1917) | 2.00 in (2022) |
| September 12 | 100.0°F (1897) | 37.0°F (1975) | 4.00 in (2008) |
| September 13 | 102.9°F (1897) | 35.1°F (1953) | 3.00 in (2008) |
| September 14 | 98.1°F (1939) | 32.0°F (1923) | 3.50 in (1961) |
| September 15 | 100.0°F (1939) | 37.9°F (1904) | 3.68 in (1894) |
| September 16 | 93.9°F (1906) | 33.1°F (1984) | 3.72 in (1921) |
| September 17 | 93.0°F (1906) | 36.0°F (1943) | 1.85 in (1978) |
| September 18 | 91.9°F (1895) | 32.0°F (1916) | 2.95 in (1968) |
| September 19 | 91.9°F (1895) | 34.0°F (1991) | 1.56 in (1900) |
| September 20 | 91.9°F (1895) | 28.9°F (1991) | 1.57 in (1978) |
| September 21 | 95.0°F (2022) | 34.0°F (1927) | 3.91 in (1947) |
| September 22 | 91.0°F (1895) | 30.0°F (1974) | 2.20 in (1970) |
| September 23 | 93.9°F (2017) | 30.0°F (1983) | 1.87 in (1964) |
| September 24 | 93.9°F (2017) | 28.9°F (1989) | 1.42 in (1961) |
| September 25 | 91.9°F (1897) | 28.9°F (1942) | 1.67 in (1981) |
| September 26 | 96.1°F (1897) | 28.9°F (1926) | 2.16 in (1904) |
| September 27 | 91.0°F (1905) | 28.9°F (1942) | 2.30 in (1907) |
| September 28 | 91.0°F (1952) | 24.1°F (1942) | 3.15 in (1999) |
| September 29 | 96.1°F (1953) | 28.9°F (1949) | 1.73 in (1893) |
| September 30 | 97.0°F (1897) | 21.9°F (1899) | 2.45 in (1919) |