| 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. 1 - Oct. 10 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 56h - Interlobate Dead Ice Moraines |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 49242 - Hillsdale, MI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 13 | 15 | 24 | 35 | 46 | 55 | 59 | 57 | 49 | 38 | 29 | 19 | 37 |
| Avg Max Temp (°F) | 29 | 33 | 44 | 56 | 69 | 78 | 82 | 80 | 73 | 60 | 46 | 34 | 57 |
| Avg Precip (In.) | 2.07 | 1.81 | 2.73 | 3.38 | 3.79 | 4.21 | 3.56 | 3.68 | 3.6 | 2.78 | 3.05 | 2.65 | 37.32 |