| 2023 Hardiness Zone: | 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 | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 53125 - Fontana, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 16 | 26 | 36 | 47 | 57 | 62 | 61 | 52 | 41 | 30 | 18 | 38 |
| Avg Max Temp (°F) | 28 | 33 | 45 | 58 | 71 | 81 | 85 | 82 | 75 | 62 | 46 | 33 | 58 |
| Avg Precip (In.) | 1.68 | 1.43 | 2.43 | 3.71 | 3.49 | 4.19 | 3.96 | 4.33 | 3.49 | 2.61 | 2.73 | 2.06 | 36.09 |