Milwaukee weather by month
Milwaukee runs from about -4°C in January to 22°C in July, with May the wettest month at 152 mm.
warmest month
July
22°C
coolest month
January
-4°C
wettest month
May
152 mm
worst air month
July
12 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | -4°C | 100 mm | 149 h | 7 |
| February | 2°C | 15 mm | 248 h | 11 |
| March | 4°C | 103 mm | 258 h | 9 |
| April | 9°C | 120 mm | 276 h | 8 |
| May | 15°C | 152 mm | 348 h | 8 |
| June | 21°C | 121 mm | 337 h | 8 |
| July | 22°C | 88 mm | 382 h | 12 |
| August | 22°C | 79 mm | 357 h | 11 |
| September | 20°C | 43 mm | 322 h | 7 |
| October | 14°C | 31 mm | 310 h | 4 |
| November | 7°C | 89 mm | 137 h | 5 |
| December | -1°C | 28 mm | 147 h | 8 |
About 3,271 hours of sun a year. Roughly 97 rainy days a year.
These are long-run climate normals, not a forecast. A given year can sit well outside them. PM2.5 is a global model: near the coast it counts sea salt as fine particulate and reads high against ground stations, sometimes by a factor of two. Use the shape of the year, not the absolute number.
where these numbers come from
- · Temperature, rainfall and sunshine: ECMWF ERA5 reanalysis climate normals via Open-Meteo (CC BY 4.0), fetched once and stored.
- · PM2.5: Copernicus CAMS reanalysis, monthly means. Modelled, not station readings; near coasts CAMS counts sea salt as PM2.5 and reads high.
Last reviewed 2026-05-24. Full method, licences and the list of sources we rejected are on the methodology page.