| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F 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 1 - May 10 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 57b - Oak Openings |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 49270 - Petersburg, MI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 16 | 18 | 27 | 36 | 47 | 57 | 61 | 59 | 51 | 40 | 31 | 22 | 39 |
| Avg Max Temp (°F) | 31 | 35 | 46 | 58 | 70 | 79 | 83 | 81 | 74 | 62 | 48 | 36 | 59 |
| Avg Precip (In.) | 1.83 | 1.73 | 2.54 | 3.21 | 3.25 | 3.67 | 3.07 | 3.52 | 3.24 | 2.41 | 2.86 | 2.56 | 33.9 |