| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 21 - Oct. 31 |
| Average Last Frost Date: | May 1 - May 10 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 53b - Kettle Moraines |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 53221 - Milwaukee, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 13 | 18 | 27 | 37 | 47 | 57 | 63 | 62 | 54 | 42 | 31 | 19 | 39 |
| Avg Max Temp (°F) | 27 | 32 | 42 | 54 | 67 | 77 | 82 | 80 | 72 | 60 | 46 | 33 | 56 |
| Avg Precip (In.) | 1.68 | 1.55 | 2.42 | 3.74 | 3.03 | 3.6 | 3.62 | 4.04 | 3.38 | 2.51 | 2.67 | 2.11 | 34.36 |