Mount Holly, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.6 °C (low) to 11.4 °C (high). Annual precipitation averages 1375.4 Millimeters. Mount Holly is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.2 °C | -2.1 °C | 97.03 mm |
| February | -11.7 °C | -0.5 °C | 83.57 mm |
| March | -7.6 °C | 3.3 °C | 113.79 mm |
| April | -2.1 °C | 10.2 °C | 110.74 mm |
| May | 5.8 °C | 17.3 °C | 115.06 mm |
| June | 10.8 °C | 21.6 °C | 140.21 mm |
| July | 13.3 °C | 24.2 °C | 122.17 mm |
| August | 12.6 °C | 23.3 °C | 116.59 mm |
| September | 7.9 °C | 20.1 °C | 112.78 mm |
| October | 2.2 °C | 12.7 °C | 138.68 mm |
| November | -3.1 °C | 6.1 °C | 106.68 mm |
| December | -9.1 °C | 0.6 °C | 118.11 mm |
| Annual | 0.6 °C | 11.4 °C | 1375.41 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |