| 2023 Hardiness Zone: | Zone 4b: -25°F to -20°F |
| 2012 Hardiness Zone: | Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F |
| 1990 Hardiness Zone: | Zone 4a: -30F to -25F |
| 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: | 51b - Central Wisconsin Undulating Till Plain |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 54479 - Spencer, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 1 | 7 | 19 | 32 | 43 | 53 | 57 | 55 | 46 | 35 | 22 | 8 | 31 |
| Avg Max Temp (°F) | 21 | 28 | 39 | 54 | 68 | 76 | 80 | 78 | 69 | 57 | 40 | 26 | 53 |
| Avg Precip (In.) | 1.03 | .89 | 1.83 | 2.79 | 3.57 | 4.24 | 4.19 | 4.39 | 4.09 | 2.47 | 2.21 | 1.24 | 32.94 |