| 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 | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 53189 - 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 | 63 | 61 | 52 | 41 | 30 | 17 | 38 |
| Avg Max Temp (°F) | 27 | 32 | 43 | 56 | 69 | 79 | 83 | 81 | 73 | 61 | 45 | 32 | 57 |
| Avg Precip (In.) | 1.46 | 1.29 | 2.24 | 3.51 | 3.05 | 3.8 | 3.85 | 4.64 | 3.49 | 2.56 | 2.58 | 1.85 | 34.31 |