| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F |
| 2012 Hardiness Zone: | Zone 4b: -25°F to -20°F |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 21 - May 31 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 51d - Central Sand Ridges |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 54423 - Custer, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 2 | 8 | 19 | 32 | 44 | 53 | 58 | 55 | 46 | 35 | 23 | 10 | 32 |
| Avg Max Temp (°F) | 22 | 28 | 39 | 54 | 68 | 76 | 80 | 77 | 69 | 57 | 40 | 27 | 53 |
| Avg Precip (In.) | 1.11 | .98 | 1.99 | 2.89 | 3.6 | 3.76 | 4.15 | 4.2 | 3.8 | 2.4 | 2.26 | 1.32 | 32.46 |