| 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 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 53097 - Mequon, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 10 | 15 | 25 | 35 | 45 | 54 | 60 | 59 | 50 | 39 | 28 | 16 | 36 |
| Avg Max Temp (°F) | 26 | 31 | 41 | 54 | 67 | 77 | 81 | 79 | 71 | 59 | 44 | 31 | 55 |
| Avg Precip (In.) | 1.4 | 1.21 | 2.04 | 3.29 | 3 | 3.73 | 3.9 | 4.2 | 3.48 | 2.46 | 2.51 | 1.79 | 33.01 |