| 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 |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 1 - May 10 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 53c - Southeastern Wisconsin Savannah and Till Plain |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 53094 - Watertown, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 7 | 12 | 24 | 35 | 46 | 56 | 61 | 59 | 50 | 39 | 27 | 14 | 36 |
| Avg Max Temp (°F) | 25 | 30 | 42 | 56 | 69 | 79 | 82 | 80 | 72 | 60 | 44 | 30 | 56 |
| Avg Precip (In.) | 1.3 | 1.22 | 2.13 | 3.18 | 3.16 | 4.18 | 4.31 | 4.36 | 3.63 | 2.53 | 2.37 | 1.66 | 34.04 |