September weather in New Boston, IL
The average temperature in New Boston in September is 66.0°F (54.5°F–77.4°F). Average precipitation: 3.34 inches.
September is a fall month in New Boston, and is warmer than the annual average of 51.2°F. Daily temperatures swing about 22.9°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 12h 16m. For travel, September is one of the best months of the year to visit.
Avg High
77.4°F
Avg Low
54.5°F
Precipitation
3.34 in
Daylight
12h 16m
September records in New Boston
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 97.0°F (2000) | 46.0°F (2009) | 2.62 in (1980) |
| September 2 | 99.0°F (2011) | 41.0°F (1946) | 0.82 in (1961) |
| September 3 | 97.0°F (2000) | 46.0°F (2017) | 1.40 in (1990) |
| September 4 | 93.0°F (1939) | 46.0°F (1997) | 1.43 in (1973) |
| September 5 | 95.0°F (2015) | 45.0°F (1997) | 1.74 in (1971) |
| September 6 | 95.0°F (2015) | 44.1°F (1997) | 1.06 in (2018) |
| September 7 | 93.9°F (2015) | 43.0°F (2025) | 2.02 in (1989) |
| September 8 | 96.1°F (1939) | 43.0°F (2025) | 2.60 in (2016) |
| September 9 | 95.0°F (1939) | 44.1°F (2024) | 1.10 in (1996) |
| September 10 | 98.1°F (2013) | 46.0°F (1998) | 2.36 in (2014) |
| September 11 | 96.1°F (2013) | 42.1°F (1997) | 0.92 in (2020) |
| September 12 | 97.0°F (2013) | 44.1°F (1997) | 1.53 in (1949) |
| September 13 | 93.9°F (1939) | 41.0°F (2014) | 3.01 in (2008) |
| September 14 | 98.1°F (2025) | 41.0°F (2014) | 3.70 in (1961) |
| September 15 | 99.0°F (2025) | 39.9°F (2007) | 1.49 in (1998) |
| September 16 | 91.0°F (2018) | 41.0°F (1979) | 1.30 in (1983) |
| September 17 | 93.9°F (2018) | 41.0°F (1999) | 1.98 in (1944) |
| September 18 | 93.9°F (2018) | 42.1°F (1999) | 1.75 in (1978) |
| September 19 | 91.0°F (2021) | 43.0°F (1979) | 2.44 in (2001) |
| September 20 | 91.9°F (2013) | 42.1°F (1943) | 1.32 in (1965) |
| September 21 | 93.0°F (2022) | 41.0°F (1943) | 4.25 in (1947) |
| September 22 | 91.0°F (2016) | 37.0°F (1979) | 2.40 in (1970) |
| September 23 | 91.0°F (2017) | 36.0°F (1979) | 1.18 in (2000) |
| September 24 | 93.0°F (2017) | 34.0°F (2012) | 2.53 in (1968) |
| September 25 | 93.9°F (2017) | 33.1°F (1942) | 2.00 in (1981) |
| September 26 | 91.0°F (2017) | 35.1°F (1940) | 1.73 in (1976) |
| September 27 | 88.0°F (1998) | 36.0°F (1942) | 1.51 in (1959) |
| September 28 | 90.0°F (1939) | 30.0°F (1942) | 3.40 in (1999) |
| September 29 | 88.0°F (2014) | 37.9°F (2022) | 0.97 in (1954) |
| September 30 | 87.1°F (2002) | 34.0°F (1947) | 0.70 in (1995) |