Petersburg, Michigan has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4 °C (low) to 15 °C (high). Annual precipitation averages 885.7 Millimeters. Petersburg is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.4 °C | 0 °C | 59.69 mm |
| February | -7.9 °C | 1.7 °C | 50.55 mm |
| March | -3.3 °C | 7.2 °C | 62.48 mm |
| April | 2.7 °C | 14.6 °C | 81.03 mm |
| May | 8.9 °C | 21 °C | 99.57 mm |
| June | 14.3 °C | 26.3 °C | 88.65 mm |
| July | 16.1 °C | 28.6 °C | 80.52 mm |
| August | 15 °C | 27.4 °C | 87.38 mm |
| September | 10.9 °C | 24.1 °C | 76.71 mm |
| October | 4.8 °C | 17 °C | 69.85 mm |
| November | -0.5 °C | 9.3 °C | 70.36 mm |
| December | -5.1 °C | 2.8 °C | 58.93 mm |
| Annual | 4 °C | 15 °C | 885.72 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |