September weather in Olney, IL
The average temperature in Olney in September is 68.1°F (55.8°F–80.4°F). Average precipitation: 3.31 inches.
September is a fall month in Olney, and is warmer than the annual average of 54.2°F. Daily temperatures swing about 24.6°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 12h 14m. For travel, September is a comfortable month to visit.
Avg High
80.4°F
Avg Low
55.8°F
Precipitation
3.31 in
Daylight
12h 14m
September records in Olney
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 105.1°F (1953) | 41.0°F (1987) | 2.15 in (1982) |
| September 2 | 106.0°F (1953) | 44.1°F (1919) | 4.66 in (1931) |
| September 3 | 105.1°F (1925) | 45.0°F (1908) | 6.43 in (1926) |
| September 4 | 102.9°F (1913) | 44.1°F (1928) | 1.72 in (1921) |
| September 5 | 106.0°F (1925) | 44.1°F (1997) | 3.23 in (1911) |
| September 6 | 104.0°F (1925) | 39.9°F (1988) | 1.10 in (1926) |
| September 7 | 102.9°F (1939) | 39.0°F (1988) | 1.51 in (1934) |
| September 8 | 105.1°F (1939) | 37.0°F (1986) | 2.21 in (2018) |
| September 9 | 104.0°F (1939) | 39.9°F (2024) | 3.25 in (2018) |
| September 10 | 102.0°F (1933) | 39.9°F (1924) | 1.84 in (1929) |
| September 11 | 98.1°F (1933) | 36.0°F (1917) | 2.05 in (1986) |
| September 12 | 99.0°F (1897) | 37.0°F (1917) | 1.33 in (1983) |
| September 13 | 102.0°F (1939) | 37.0°F (1902) | 2.40 in (1943) |
| September 14 | 102.9°F (1939) | 35.1°F (1902) | 2.21 in (1989) |
| September 15 | 104.0°F (1939) | 41.0°F (1902) | 1.24 in (1956) |
| September 16 | 100.0°F (1927) | 33.1°F (1916) | 2.58 in (1996) |
| September 17 | 99.0°F (1927) | 37.0°F (1937) | 2.70 in (2016) |
| September 18 | 99.0°F (1953) | 37.0°F (1901) | 2.18 in (1904) |
| September 19 | 98.1°F (1925) | 33.1°F (1916) | 2.06 in (2011) |
| September 20 | 100.0°F (1940) | 34.0°F (1918) | 2.70 in (1954) |
| September 21 | 100.0°F (1940) | 34.0°F (1918) | 2.75 in (1947) |
| September 22 | 97.0°F (2022) | 33.1°F (1918) | 1.40 in (1993) |
| September 23 | 93.9°F (1941) | 32.0°F (1983) | 1.42 in (1993) |
| September 24 | 93.9°F (1939) | 28.9°F (1928) | 1.43 in (1973) |
| September 25 | 91.9°F (1908) | 34.0°F (1950) | 2.59 in (2000) |
| September 26 | 93.9°F (1897) | 27.0°F (1928) | 2.83 in (2012) |
| September 27 | 91.9°F (2017) | 33.1°F (1940) | 1.95 in (2003) |
| September 28 | 97.0°F (1939) | 28.0°F (1942) | 2.35 in (1911) |
| September 29 | 100.9°F (1953) | 32.0°F (1942) | 3.30 in (2015) |
| September 30 | 96.1°F (1964) | 27.0°F (1899) | 2.52 in (1955) |