Haverhill, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.3 °F (low) to 56.4 °F (high). Annual precipitation averages 38.8 Inches. Haverhill is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.8 °F | 28.7 °F | 2.41 in. |
| February | 6.8 °F | 32.4 °F | 2.08 in. |
| March | 17.4 °F | 41.5 °F | 2.44 in. |
| April | 29.8 °F | 55.1 °F | 2.95 in. |
| May | 41.7 °F | 68.0 °F | 3.41 in. |
| June | 50.9 °F | 76.5 °F | 3.97 in. |
| July | 56.5 °F | 81.6 °F | 4.13 in. |
| August | 54.4 °F | 80.4 °F | 3.75 in. |
| September | 47.0 °F | 72.9 °F | 3.57 in. |
| October | 35.1 °F | 58.7 °F | 4.19 in. |
| November | 25.8 °F | 46.2 °F | 2.8 in. |
| December | 15.3 °F | 34.5 °F | 3.14 in. |
| Annual | 32.3 °F | 56.4 °F | 38.84 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |