| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 56f - Lake Michigan Moraines |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 49345 - Sparta, MI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 14 | 15 | 23 | 34 | 44 | 53 | 58 | 57 | 49 | 39 | 29 | 20 | 36 |
| Avg Max Temp (°F) | 29 | 33 | 43 | 56 | 69 | 78 | 82 | 80 | 72 | 60 | 46 | 34 | 57 |
| Avg Precip (In.) | 2.32 | 1.55 | 2.58 | 3.22 | 3.4 | 3.38 | 2.93 | 4.21 | 3.86 | 3.07 | 3.3 | 2.64 | 36.48 |