Climate averages 1991–2020
Milwaukee weather
in September.
A mild, moderately wet month: the 4th warmest and the 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Milwaukee: daytime highs average 20.8°C and nights cool to about 16.2°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 76 mm of rain on roughly 9 days, which makes September a moderately wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 33 min on an average September day.
The nearest other city in this atlas is Waukesha (27 km away). In September its highs average 22.0°C, 1.2°C warmer than Milwaukee, with 75 mm of rain.
Among the 498 cities listed in the United States, Milwaukee ranks joint 486th of 498 for the warmest September highs and joint 255th of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Milwaukee is 6.1°C cooler than that mean.
From September to October, average highs fall by 6.8°C to 14.0°C, and monthly rainfall rises from 76 mm to 78 mm.
The annual picture
September in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Milwaukee climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -2.1°C-7.8°C | -7.8°C | 51 | 8.9 | 9.49 h |
| February | -1.3°C-7.3°C | -7.3°C | 48 | 7.1 | 10.510 h |
| March | 2.7°C-3.0°C | -3.0°C | 61 | 9.5 | 11.912 h |
| April | 7.9°C3.0°C | 3.0°C | 105 | 11.9 | 13.413 h |
| May | 14.4°C9.4°C | 9.4°C | 91 | 11.5 | 14.615 h |
| June | 21.0°C16.1°C | 16.1°C | 89 | 10.8 | 15.315 h |
| July | 24.9°C20.1°C | 20.1°C | 80 | 10.1 | 15.015 h |
| August | 24.4°C20.0°C | 20.0°C | 91 | 10.7 | 13.914 h |
| September, selected | 20.8°C16.2°C | 16.2°C | 76 | 9.2 | 12.513 h |
| October | 14.0°C9.5°C | 9.5°C | 78 | 9.1 | 11.111 h |
| November | 6.8°C2.5°C | 2.5°C | 62 | 8.6 | 9.810 h |
| December | 1.1°C-3.5°C | -3.5°C | 55 | 8.5 | 9.19 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Waukesha in SeptemberUnited States · 27 kmHigh 22.0°C · Low 14.2°C · 75 mm rain
- Racine in SeptemberUnited States · 36 kmHigh 20.8°C · Low 17.0°C · 81 mm rain
- Kenosha in SeptemberUnited States · 51 kmHigh 21.0°C · Low 17.1°C · 80 mm rain
- Waukegan in SeptemberUnited States · 75 kmHigh 21.2°C · Low 17.1°C · 83 mm rain
- Arlington Heights in SeptemberUnited States · 106 kmHigh 22.7°C · Low 15.1°C · 75 mm rain
- Evanston in SeptemberUnited States · 112 kmHigh 22.1°C · Low 16.4°C · 74 mm rain
- Schaumburg in SeptemberUnited States · 113 kmHigh 22.9°C · Low 14.2°C · 75 mm rain
- Elgin in SeptemberUnited States · 116 kmHigh 23.1°C · Low 14.3°C · 78 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Milwaukee) is explained once on the Milwaukee year overview and on the Sources, method and limits page.