September weather in Green Bay, WI
The average temperature in Green Bay in September is 60.2°F (49.4°F–71.0°F). Average precipitation: 3.39 inches.
September is a fall month in Green Bay, and is warmer than the annual average of 44.7°F. Daily temperatures swing about 21.6°F between overnight low and afternoon high. Daylight averages about 12h 17m. For travel, September is a comfortable month to visit.
Avg High
71.0°F
Avg Low
49.4°F
Precipitation
3.39 in
Daylight
12h 17m
September records in Green Bay
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 93.9°F (2000) | 41.0°F (2009) | 1.02 in (2014) |
| September 2 | 89.1°F (2008) | 45.0°F (2009) | 0.87 in (2002) |
| September 3 | 90.0°F (2008) | 43.0°F (2025) | 1.39 in (2019) |
| September 4 | 91.9°F (2023) | 42.1°F (2025) | 1.99 in (2018) |
| September 5 | 91.0°F (2023) | 43.0°F (2003) | 2.30 in (2014) |
| September 6 | 91.0°F (2007) | 39.9°F (2011) | 0.29 in (2024) |
| September 7 | 88.0°F (2015) | 42.1°F (2011) | 1.12 in (2015) |
| September 8 | 89.1°F (2002) | 41.0°F (2017) | 0.86 in (2007) |
| September 9 | 82.0°F (2003) | 41.0°F (2010) | 1.86 in (2015) |
| September 10 | 89.1°F (2002) | 41.0°F (2008) | 1.30 in (2019) |
| September 11 | 90.0°F (2013) | 37.0°F (2020) | 1.15 in (2000) |
| September 12 | 88.0°F (2005) | 37.9°F (2014) | 1.62 in (2022) |
| September 13 | 86.0°F (2005) | 37.9°F (2014) | 1.07 in (2019) |
| September 14 | 84.9°F (2004) | 41.0°F (2001) | 1.56 in (2003) |
| September 15 | 84.9°F (2009) | 33.1°F (2007) | 0.86 in (2004) |
| September 16 | 86.0°F (2018) | 36.0°F (2011) | 0.93 in (2010) |
| September 17 | 87.1°F (2017) | 37.0°F (2013) | 0.20 in (2016) |
| September 18 | 88.0°F (2018) | 37.0°F (2013) | 0.89 in (2018) |
| September 19 | 84.9°F (2000) | 34.0°F (2012) | 0.77 in (2015) |
| September 20 | 84.0°F (2021) | 37.9°F (2006) | 1.01 in (2019) |
| September 21 | 81.0°F (2016) | 36.0°F (2006) | 1.05 in (2002) |
| September 22 | 90.0°F (2017) | 36.0°F (2006) | 1.20 in (2016) |
| September 23 | 89.1°F (2017) | 34.0°F (2012) | 1.97 in (2010) |
| September 24 | 90.0°F (2017) | 34.0°F (2012) | 0.59 in (2010) |
| September 25 | 90.0°F (2017) | 33.1°F (2000) | 0.44 in (2007) |
| September 26 | 90.0°F (2017) | 35.1°F (2000) | 0.61 in (2011) |
| September 27 | 80.1°F (2014) | 35.1°F (2012) | 0.82 in (2011) |
| September 28 | 81.0°F (2025) | 33.1°F (2000) | 1.04 in (2019) |
| September 29 | 81.0°F (2014) | 32.0°F (2003) | 0.69 in (2005) |
| September 30 | 80.1°F (2025) | 32.0°F (2009) | 0.42 in (2011) |