September weather in Brookfield, WI
The average temperature in Brookfield in September is 61.8°F (51.3°F–72.2°F). Average precipitation: 3.21 inches.
September is a fall month in Brookfield, and is warmer than the annual average of 46.6°F. Daily temperatures swing about 20.9°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 12h 17m. For travel, September is one of the best months of the year to visit.
Avg High
72.2°F
Avg Low
51.3°F
Precipitation
3.21 in
Daylight
12h 17m
September records in Brookfield
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 90.0°F (2012) | 42.1°F (2009) | 0.98 in (2010) |
| September 2 | 91.9°F (2011) | 42.1°F (2009) | 0.52 in (2018) |
| September 3 | 93.0°F (2008) | 42.1°F (2009) | 0.86 in (2018) |
| September 4 | 93.0°F (2023) | 42.1°F (2025) | 0.75 in (2018) |
| September 5 | 91.0°F (2023) | 44.1°F (2010) | 1.55 in (2008) |
| September 6 | 90.0°F (2007) | 44.1°F (2011) | 1.85 in (2018) |
| September 7 | 91.0°F (2016) | 43.0°F (2024) | 0.13 in (2016) |
| September 8 | 84.0°F (2015) | 41.0°F (2025) | 1.45 in (2016) |
| September 9 | 82.9°F (2022) | 43.0°F (2017) | 0.65 in (2015) |
| September 10 | 87.1°F (2013) | 41.0°F (2008) | 0.43 in (2019) |
| September 11 | 91.9°F (2013) | 42.1°F (2017) | 2.00 in (2022) |
| September 12 | 86.0°F (2019) | 41.0°F (2007) | 5.81 in (2022) |
| September 13 | 86.0°F (2012) | 39.0°F (2014) | 1.85 in (2019) |
| September 14 | 82.9°F (2009) | 41.0°F (2013) | 0.47 in (2021) |
| September 15 | 84.0°F (2009) | 34.0°F (2007) | 0.46 in (2008) |
| September 16 | 84.9°F (2017) | 37.0°F (2011) | 0.37 in (2013) |
| September 17 | 87.1°F (2024) | 39.0°F (2013) | 0.23 in (2023) |
| September 18 | 88.0°F (2018) | 43.0°F (2012) | 1.60 in (2015) |
| September 19 | 86.0°F (2007) | 33.1°F (2012) | 0.87 in (2011) |
| September 20 | 87.1°F (2024) | 33.1°F (2012) | 1.10 in (2016) |
| September 21 | 88.0°F (2017) | 42.1°F (2012) | 0.90 in (2018) |
| September 22 | 86.0°F (2007) | 37.0°F (2014) | 2.00 in (2024) |
| September 23 | 93.0°F (2017) | 34.0°F (2012) | 1.39 in (2025) |
| September 24 | 91.9°F (2017) | 33.1°F (2012) | 0.08 in (2016) |
| September 25 | 90.0°F (2017) | 41.0°F (2012) | 0.92 in (2011) |
| September 26 | 91.0°F (2017) | 43.0°F (2010) | 1.29 in (2023) |
| September 27 | 86.0°F (2017) | 37.0°F (2010) | 1.27 in (2023) |
| September 28 | 82.9°F (2025) | 39.0°F (2022) | 0.85 in (2009) |
| September 29 | 80.1°F (2013) | 34.0°F (2018) | 0.95 in (2019) |
| September 30 | 84.9°F (2025) | 34.0°F (2018) | 0.39 in (2018) |