Madison weather by month
Madison runs from about -5°C in January to 22°C in July, with April the wettest month at 152 mm.
warmest month
July
22°C
coolest month
January
-5°C
wettest month
April
152 mm
worst air month
February
10 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | -5°C | 73 mm | 141 h | 7 |
| February | 1°C | 16 mm | 262 h | 10 |
| March | 4°C | 98 mm | 265 h | 10 |
| April | 9°C | 152 mm | 257 h | 6 |
| May | 16°C | 122 mm | 339 h | 5 |
| June | 21°C | 113 mm | 315 h | 6 |
| July | 22°C | 108 mm | 371 h | 9 |
| August | 22°C | 66 mm | 359 h | 10 |
| September | 19°C | 11 mm | 340 h | 8 |
| October | 13°C | 36 mm | 304 h | 5 |
| November | 6°C | 77 mm | 150 h | 5 |
| December | -3°C | 32 mm | 137 h | 8 |
About 3,240 hours of sun a year. Roughly 91 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 2026-05-23. Full method, licences and the list of sources we rejected are on the methodology page.