Wilton, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.7 °F (low) to 58.3 °F (high). Annual precipitation averages 48.7 Inches. Wilton 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 | 13.9 °F | 32.8 °F | 3.51 in. |
| February | 15.2 °F | 35.9 °F | 3.35 in. |
| March | 23.4 °F | 43.9 °F | 4.06 in. |
| April | 34.1 °F | 57.1 °F | 4.1 in. |
| May | 44.8 °F | 68.2 °F | 3.88 in. |
| June | 54.2 °F | 77.1 °F | 4.32 in. |
| July | 59.5 °F | 82.4 °F | 3.98 in. |
| August | 57.6 °F | 80.7 °F | 3.93 in. |
| September | 49.8 °F | 73.4 °F | 4.11 in. |
| October | 38.5 °F | 60.5 °F | 5.07 in. |
| November | 29.1 °F | 49.2 °F | 3.97 in. |
| December | 20.3 °F | 38.2 °F | 4.45 in. |
| Annual | 36.7 °F | 58.3 °F | 48.73 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 |