Hart, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.1 °C (low) to 12.9 °C (high). Annual precipitation averages 957.3 Millimeters. Hart is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.3 °C | -1.4 °C | 69.09 mm |
| February | -8.2 °C | -0.1 °C | 55.37 mm |
| March | -4.8 °C | 4.9 °C | 55.88 mm |
| April | 1.2 °C | 12.1 °C | 90.42 mm |
| May | 6.9 °C | 18.8 °C | 96.01 mm |
| June | 12.2 °C | 23.9 °C | 87.12 mm |
| July | 15 °C | 26 °C | 84.33 mm |
| August | 14.3 °C | 25.3 °C | 89.15 mm |
| September | 10.2 °C | 21.8 °C | 81.53 mm |
| October | 4.5 °C | 14.7 °C | 103.12 mm |
| November | -0.4 °C | 7.4 °C | 79.76 mm |
| December | -4.9 °C | 1.3 °C | 65.53 mm |
| Annual | 3.1 °C | 12.9 °C | 957.31 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| 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 | Dfb - Humid Continental Mild Summer, Wet All Year |