Milwaukee weather in September
September in Milwaukee: nice, rainy, with clean air — an excellent time to visit.
#4 of 12 months in Milwaukee · #288 of 604 destinations to visit in September · comfort 81/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Milwaukee climate normals — September
| Daytime high | 21°C / 70°F | 😎 nice |
|---|---|---|
| Nighttime low | 17°C / 62°F | |
| Feels like (high) | 21°C / 70°F | |
| Rainfall | 106 mm / 4.2 in | 🌧 rainy |
| Rainy days | 11 days | |
| Humidity | 76% | 💦 very humid |
| Dew point | 14°C / 58°F | |
| Sunshine | 8.9 h/day | |
| Daylight | 12.5 h | |
| Wind | 21 km/h / 13 mph | |
| Air quality (US AQI) | 44 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Milwaukee in September — FAQ
- Is September a good time to visit Milwaukee?
- September in Milwaukee: nice, rainy, with clean air — an excellent time to visit. It ranks #4 of 12 months for Milwaukee on SeasonMap's comfort score (81/100).
- What is the weather like in Milwaukee in September?
- In September, Milwaukee averages a daily high of 21.2°C and a low of 16.9°C, with about 105.7 mm of rain over roughly 11.2 rainy days.
- What is the air quality in Milwaukee in September?
- Milwaukee has a mean US Air Quality Index of about 44 in September.