| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 11 - May 20 |
| 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 53188 - Waukesha, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 16 | 26 | 37 | 48 | 57 | 62 | 61 | 52 | 41 | 29 | 17 | 38 |
| Avg Max Temp (°F) | 27 | 32 | 43 | 56 | 69 | 79 | 83 | 81 | 73 | 60 | 45 | 32 | 57 |
| Avg Precip (In.) | 1.45 | 1.27 | 2.22 | 3.48 | 3.05 | 3.83 | 3.88 | 4.59 | 3.49 | 2.55 | 2.55 | 1.84 | 34.21 |