Mars Hill, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.7 °C (low) to 10.7 °C (high). Annual precipitation averages 1095.5 Millimeters. Mars Hill is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -16.7 °C | -5.5 °C | 87.63 mm |
| February | -15.9 °C | -3.8 °C | 65.28 mm |
| March | -9.5 °C | 1.7 °C | 77.98 mm |
| April | -1.7 °C | 9.2 °C | 82.55 mm |
| May | 4.8 °C | 17.6 °C | 90.93 mm |
| June | 10.1 °C | 22.8 °C | 108.2 mm |
| July | 13.2 °C | 25.5 °C | 101.35 mm |
| August | 12.1 °C | 24.8 °C | 92.2 mm |
| September | 7.9 °C | 20.3 °C | 88.9 mm |
| October | 2.1 °C | 12.5 °C | 109.73 mm |
| November | -3.6 °C | 4.6 °C | 93.47 mm |
| December | -11 °C | -1.8 °C | 97.28 mm |
| Annual | -0.7 °C | 10.7 °C | 1095.5 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |