| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 21 - May 31 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 51g - Door Peninsula |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 54246 - Washington Island, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 9 | 10 | 20 | 31 | 41 | 51 | 58 | 58 | 51 | 41 | 29 | 18 | 35 |
| Avg Max Temp (°F) | 24 | 26 | 35 | 45 | 60 | 68 | 73 | 72 | 65 | 53 | 41 | 29 | 49 |
| Avg Precip (In.) | 1.84 | 1.19 | 2.03 | 2.44 | 2.62 | 2.9 | 3.06 | 3.47 | 3.43 | 2.69 | 2.4 | 1.84 | 29.88 |