Mont Vernon, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.6 °F (low) to 56.7 °F (high). Annual precipitation averages 48.9 Inches. Mont Vernon is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.7 °F | 31.0 °F | 3.51 in. |
| February | 14.1 °F | 34.1 °F | 3.37 in. |
| March | 21.7 °F | 42.2 °F | 4.01 in. |
| April | 32.5 °F | 55.7 °F | 4.03 in. |
| May | 43.7 °F | 66.9 °F | 3.87 in. |
| June | 53.1 °F | 75.7 °F | 4.39 in. |
| July | 58.4 °F | 80.7 °F | 4.02 in. |
| August | 56.6 °F | 79.0 °F | 3.95 in. |
| September | 49.1 °F | 72.0 °F | 4.14 in. |
| October | 38.0 °F | 58.9 °F | 5.14 in. |
| November | 28.6 °F | 47.3 °F | 3.99 in. |
| December | 19.1 °F | 36.4 °F | 4.47 in. |
| Annual | 35.6 °F | 56.7 °F | 48.89 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |