Wisconsin climate by month
January highs across Wisconsin range from 26°F in Green Bay to 31°F in Milwaukee; July highs from 76°F in Sister Bay to 83°F in Wisconsin Dells. The most common best months across these cities are May, June, September.
Wisconsin weather month by month
Average of the 5 Wisconsin cities on this site, computed from NOAA's unrounded values (so it can differ by a degree from averaging the rounded city figures); individual cities differ, sometimes a lot.
| Month | High | Low | Wet days | Snow |
|---|---|---|---|---|
| January | 27°F | 12°F | 10 | 13.9 in |
| February | 31°F | 14°F | 9 | 12.0 in |
| March | 42°F | 24°F | 10 | 7.4 in |
| April | 54°F | 34°F | 11 | 3.4 in |
| May | 66°F | 45°F | 12 | 0.02 in |
| June | 76°F | 56°F | 11 | 0.0 in |
| July | 81°F | 61°F | 10 | 0.0 in |
| August | 79°F | 59°F | 10 | 0.0 in |
| September | 72°F | 51°F | 9 | 0.0 in |
| October | 59°F | 40°F | 10 | 0.4 in |
| November | 45°F | 29°F | 9 | 2.8 in |
| December | 33°F | 19°F | 10 | 11.2 in |
Regional differences
- Warmest winterMilwaukee: January high 31°F
- Coolest summerSister Bay: July high 76°F
- Most wet daysGreen Bay: 126 a year
- Fewest wet daysWisconsin Dells: 112 a year
- Most snowSister Bay: 58.8 in a year
Warmest and coolest Wisconsin city each month
| Month | Warmest | Coolest | Best month for |
|---|---|---|---|
| January | Milwaukee 31°F | Green Bay 26°F | – |
| February | Milwaukee 34°F | Sister Bay 28°F | – |
| March | Milwaukee 44°F | Sister Bay 36°F | – |
| April | Madison 57°F | Sister Bay 47°F | – |
| May | Wisconsin Dells 69°F | Sister Bay 59°F | 4 cities |
| June | Wisconsin Dells 79°F | Sister Bay 70°F | 3 cities |
| July | Wisconsin Dells 83°F | Sister Bay 76°F | 1 city |
| August | Wisconsin Dells 81°F | Sister Bay 75°F | 1 city |
| September | Milwaukee 74°F | Sister Bay 68°F | 2 cities |
| October | Milwaukee 61°F | Sister Bay 55°F | – |
| November | Milwaukee 48°F | Sister Bay 42°F | – |
| December | Milwaukee 36°F | Green Bay 31°F | – |
By normal daily high. "Best month for": how many of the 5 cities have it among their best months by our comfort score.
Frost and humidity across Wisconsin
- Earliest typical last frostMilwaukee: Apr 19
- Latest typical last frostSister Bay: May 14
- Most muggy daysMadison: 28 a year
- Fewest muggy daysGreen Bay: 23 a year
All Wisconsin cities
| City | Jan high | Jul high | Wet days/yr | Snow/yr | Best months |
|---|---|---|---|---|---|
| Green Bay | 26°F | 81°F | 126 | 55.6 in | May, Jun, Sep |
| Madison | 27°F | 82°F | 126 | 51.8 in | May |
| Milwaukee | 31°F | 82°F | 125 | 48.7 in | May, Jun, Sep |
| Sister Bay | 26°F | 76°F | 116 | 58.8 in | Jun, Jul, Aug |
| Wisconsin Dells | 26°F | 83°F | 112 | 40.7 in | May |