September weather in Sussex, WI
The average temperature in Sussex in September is 62.0°F (51.0°F–72.9°F). Average precipitation: 3.30 inches.
September is a fall month in Sussex, and is warmer than the annual average of 46.5°F. Daily temperatures swing about 21.9°F between overnight low and afternoon high. Daylight averages about 12h 17m. For travel, September is one of the best months of the year to visit.
Avg High
72.9°F
Avg Low
51.0°F
Precipitation
3.30 in
Daylight
12h 17m
September records in Sussex
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 86.0°F (2011) | 46.0°F (2017) | 0.63 in (2010) |
| September 2 | 91.0°F (2015) | 46.9°F (2017) | 0.85 in (2018) |
| September 3 | 91.0°F (2015) | 48.0°F (2013) | 1.31 in (2018) |
| September 4 | 93.9°F (2023) | 42.1°F (2025) | 0.42 in (2018) |
| September 5 | 91.9°F (2023) | 41.0°F (2025) | 0.95 in (2012) |
| September 6 | 91.0°F (2015) | 44.1°F (2017) | 1.04 in (2018) |
| September 7 | 93.0°F (2015) | 43.0°F (2024) | 1.03 in (2016) |
| September 8 | 89.1°F (2015) | 42.1°F (2024) | 1.81 in (2016) |
| September 9 | 84.9°F (2022) | 41.0°F (2025) | 1.62 in (2015) |
| September 10 | 86.0°F (2013) | 46.9°F (2017) | 0.64 in (2019) |
| September 11 | 90.0°F (2013) | 41.0°F (2012) | 0.60 in (2022) |
| September 12 | 88.0°F (2019) | 39.9°F (2014) | 4.32 in (2022) |
| September 13 | 87.1°F (2011) | 37.0°F (2014) | 1.51 in (2019) |
| September 14 | 82.0°F (2024) | 39.0°F (2014) | 0.68 in (2021) |
| September 15 | 86.0°F (2024) | 37.0°F (2011) | 0.17 in (2019) |
| September 16 | 89.1°F (2024) | 37.0°F (2011) | 0.39 in (2013) |
| September 17 | 90.0°F (2024) | 39.9°F (2013) | 0.84 in (2023) |
| September 18 | 88.0°F (2015) | 42.1°F (2012) | 2.10 in (2015) |
| September 19 | 87.1°F (2025) | 36.0°F (2012) | 0.85 in (2011) |
| September 20 | 89.1°F (2024) | 37.0°F (2020) | 0.85 in (2013) |
| September 21 | 91.0°F (2017) | 43.0°F (2020) | 0.37 in (2016) |
| September 22 | 90.0°F (2024) | 36.0°F (2014) | 0.46 in (2016) |
| September 23 | 95.0°F (2017) | 34.0°F (2022) | 0.89 in (2024) |
| September 24 | 90.0°F (2017) | 35.1°F (2022) | 0.08 in (2022) |
| September 25 | 90.0°F (2017) | 37.0°F (2012) | 0.49 in (2011) |
| September 26 | 86.0°F (2017) | 41.0°F (2022) | 1.06 in (2011) |
| September 27 | 84.9°F (2017) | 37.9°F (2022) | 1.30 in (2023) |
| September 28 | 84.9°F (2025) | 36.0°F (2022) | 0.75 in (2023) |
| September 29 | 82.0°F (2015) | 30.9°F (2022) | 0.99 in (2015) |
| September 30 | 88.0°F (2025) | 32.0°F (2022) | 0.61 in (2019) |