Henniker, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.1 °F (low) to 57.1 °F (high). Annual precipitation averages 48.1 Inches. Henniker 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 11.3 °F | 31.1 °F | 3.29 in. |
| February | 12.8 °F | 34.2 °F | 3.23 in. |
| March | 21.3 °F | 42.4 °F | 3.71 in. |
| April | 32.2 °F | 55.7 °F | 3.89 in. |
| May | 43.5 °F | 67.5 °F | 3.74 in. |
| June | 53.0 °F | 76.5 °F | 4.48 in. |
| July | 58.4 °F | 81.9 °F | 4.14 in. |
| August | 56.3 °F | 80.2 °F | 3.9 in. |
| September | 48.7 °F | 72.7 °F | 4.06 in. |
| October | 37.0 °F | 59.3 °F | 5.12 in. |
| November | 28.1 °F | 47.5 °F | 4.0 in. |
| December | 18.6 °F | 36.6 °F | 4.53 in. |
| Annual | 35.1 °F | 57.1 °F | 48.09 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 5a : -20°F to -15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |