September weather in Quincy, IL
The average temperature in Quincy in September is 68.0°F (57.1°F–78.9°F). Average precipitation: 3.37 inches.
September is a fall month in Quincy, and is warmer than the annual average of 53.7°F. Daily temperatures swing about 21.8°F between overnight low and afternoon high. Expect about 6 days with precipitation. Daylight averages about 12h 15m. For travel, September is one of the best months of the year to visit.
Avg High
78.9°F
Avg Low
57.1°F
Precipitation
3.37 in
Daylight
12h 15m
September records in Quincy
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 99.0°F (2013) | 48.9°F (1967) | 3.15 in (2003) |
| September 2 | 102.9°F (2011) | 46.9°F (1946) | 1.50 in (1980) |
| September 3 | 100.0°F (2011) | 46.9°F (1946) | 1.00 in (1941) |
| September 4 | 100.0°F (1947) | 50.0°F (1984) | 2.15 in (1991) |
| September 5 | 96.1°F (1990) | 48.9°F (1997) | 1.10 in (2008) |
| September 6 | 98.1°F (1990) | 44.1°F (1988) | 2.25 in (2018) |
| September 7 | 98.1°F (1990) | 44.1°F (1988) | 1.33 in (1965) |
| September 8 | 98.1°F (1978) | 43.0°F (2024) | 0.96 in (1973) |
| September 9 | 95.0°F (1980) | 43.0°F (2024) | 2.29 in (1989) |
| September 10 | 100.9°F (2013) | 46.9°F (1967) | 3.20 in (2014) |
| September 11 | 95.0°F (1978) | 45.0°F (1940) | 2.52 in (1975) |
| September 12 | 98.1°F (2013) | 39.9°F (1940) | 2.33 in (1949) |
| September 13 | 93.9°F (1939) | 43.0°F (1940) | 3.58 in (1977) |
| September 14 | 93.0°F (1939) | 43.0°F (2014) | 3.55 in (1961) |
| September 15 | 96.1°F (2025) | 43.0°F (1979) | 1.09 in (1967) |
| September 16 | 91.0°F (2018) | 37.9°F (1937) | 1.67 in (1978) |
| September 17 | 93.9°F (1997) | 41.0°F (1979) | 2.67 in (1944) |
| September 18 | 93.9°F (1947) | 42.1°F (1943) | 1.13 in (1982) |
| September 19 | 93.9°F (2007) | 39.9°F (1991) | 2.21 in (2010) |
| September 20 | 100.0°F (1940) | 37.0°F (1991) | 1.35 in (2013) |
| September 21 | 96.1°F (2016) | 36.0°F (1991) | 3.79 in (1947) |
| September 22 | 96.1°F (1937) | 36.0°F (1983) | 2.05 in (1970) |
| September 23 | 93.0°F (2017) | 32.0°F (1983) | 1.70 in (2019) |
| September 24 | 93.9°F (2017) | 35.1°F (1989) | 4.14 in (1970) |
| September 25 | 93.0°F (2007) | 30.0°F (1937) | 1.18 in (1941) |
| September 26 | 91.9°F (2016) | 34.0°F (1989) | 1.80 in (1976) |
| September 27 | 88.0°F (1946) | 35.1°F (1942) | 1.40 in (2012) |
| September 28 | 90.0°F (1990) | 30.9°F (1942) | 1.85 in (2019) |
| September 29 | 91.0°F (2021) | 35.1°F (1984) | 1.30 in (1999) |
| September 30 | 91.0°F (2002) | 33.1°F (1984) | 1.45 in (1978) |