September weather in Sullivan, IN
The average temperature in Sullivan in September is 68.2°F (57.1°F–79.4°F). Average precipitation: 3.59 inches.
September is a fall month in Sullivan, and is warmer than the annual average of 54.4°F. Daily temperatures swing about 22.3°F between overnight low and afternoon high. Daylight averages about 12h 14m. For travel, September is one of the best months of the year to visit.
Avg High
79.4°F
Avg Low
57.1°F
Precipitation
3.59 in
Daylight
12h 14m
September records in Sullivan
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 95.0°F (2013) | 50.0°F (2009) | 1.12 in (1989) |
| September 2 | 97.0°F (2011) | 48.9°F (1994) | 3.32 in (2014) |
| September 3 | 97.0°F (2011) | 48.9°F (1994) | 2.73 in (1993) |
| September 4 | 97.0°F (2011) | 45.0°F (1997) | 2.05 in (2022) |
| September 5 | 96.1°F (1999) | 45.0°F (1997) | 0.87 in (1994) |
| September 6 | 95.0°F (1999) | 46.9°F (2010) | 1.21 in (2022) |
| September 7 | 93.9°F (1990) | 45.0°F (2017) | 1.52 in (1992) |
| September 8 | 95.0°F (2002) | 45.0°F (2017) | 2.50 in (2012) |
| September 9 | 93.0°F (2002) | 46.0°F (2024) | 3.90 in (2018) |
| September 10 | 95.0°F (2002) | 45.0°F (1999) | 1.31 in (1992) |
| September 11 | 95.0°F (2002) | 45.0°F (1993) | 2.25 in (2000) |
| September 12 | 93.0°F (2013) | 48.0°F (2007) | 2.70 in (2006) |
| September 13 | 95.0°F (1991) | 45.0°F (2015) | 1.92 in (2008) |
| September 14 | 96.1°F (1991) | 41.0°F (1996) | 1.65 in (1989) |
| September 15 | 93.0°F (1991) | 43.0°F (1996) | 1.29 in (1993) |
| September 16 | 93.0°F (1991) | 43.0°F (2011) | 1.20 in (1996) |
| September 17 | 91.0°F (1991) | 45.0°F (2000) | 2.58 in (2016) |
| September 18 | 91.0°F (2017) | 45.0°F (1999) | 1.45 in (2006) |
| September 19 | 91.0°F (2018) | 39.0°F (2012) | 1.20 in (2017) |
| September 20 | 91.0°F (2018) | 36.0°F (1991) | 2.09 in (2011) |
| September 21 | 91.9°F (2018) | 39.0°F (1991) | 1.44 in (2002) |
| September 22 | 93.9°F (2010) | 36.0°F (1999) | 1.51 in (2003) |
| September 23 | 91.0°F (2017) | 32.0°F (1995) | 1.04 in (1993) |
| September 24 | 93.0°F (2010) | 35.1°F (1995) | 1.81 in (1994) |
| September 25 | 91.0°F (2007) | 37.0°F (2012) | 1.28 in (2009) |
| September 26 | 90.0°F (2017) | 36.0°F (2001) | 1.75 in (2000) |
| September 27 | 91.0°F (2017) | 36.0°F (1991) | 1.76 in (2003) |
| September 28 | 91.0°F (1998) | 37.9°F (1989) | 0.75 in (2024) |
| September 29 | 89.1°F (1999) | 34.0°F (2003) | 0.78 in (2005) |
| September 30 | 88.0°F (2019) | 32.0°F (2003) | 0.89 in (2015) |