Gilmanton, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.4 °F (low) to 55.3 °F (high). Annual precipitation averages 45.5 Inches. Gilmanton is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.5 °F | 29.1 °F | 2.78 in. |
| February | 14.0 °F | 32.2 °F | 2.99 in. |
| March | 21.9 °F | 40.7 °F | 3.23 in. |
| April | 33.5 °F | 53.9 °F | 3.58 in. |
| May | 44.0 °F | 66.8 °F | 3.71 in. |
| June | 53.7 °F | 75.0 °F | 4.57 in. |
| July | 58.9 °F | 80.1 °F | 4.29 in. |
| August | 57.7 °F | 78.4 °F | 4.13 in. |
| September | 49.9 °F | 70.6 °F | 4.28 in. |
| October | 39.5 °F | 57.2 °F | 4.77 in. |
| November | 30.1 °F | 45.4 °F | 3.57 in. |
| December | 20.4 °F | 34.7 °F | 3.63 in. |
| Annual | 36.4 °F | 55.3 °F | 45.53 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°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 |