| 2023 Hardiness Zone: | Zone 5b: -15°F to -10°F | |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F | |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F | |
| 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: | 53c - Southeastern Wisconsin Savannah and Till Plain | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 53538 - Fort Atkinson, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 8 | 13 | 24 | 36 | 46 | 56 | 61 | 58 | 49 | 39 | 27 | 15 | 36 |
| Avg Max Temp (°F) | 26 | 31 | 43 | 57 | 70 | 79 | 83 | 81 | 73 | 61 | 45 | 31 | 57 |
| Avg Precip (In.) | 1.37 | 1.3 | 2.14 | 3.41 | 3.26 | 3.89 | 3.98 | 4.24 | 3.43 | 2.53 | 2.49 | 1.65 | 33.71 |