Unity, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.9 °F (low) to 54.2 °F (high). Annual precipitation averages 46.7 Inches. Unity is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.2 °F | 27.9 °F | 3.4 in. |
| February | 13.4 °F | 30.9 °F | 3.1 in. |
| March | 21.4 °F | 39.2 °F | 3.23 in. |
| April | 33.0 °F | 52.8 °F | 3.44 in. |
| May | 43.9 °F | 65.2 °F | 3.9 in. |
| June | 53.9 °F | 73.5 °F | 4.66 in. |
| July | 59.1 °F | 78.4 °F | 4.36 in. |
| August | 56.6 °F | 76.9 °F | 4.09 in. |
| September | 49.4 °F | 69.9 °F | 3.67 in. |
| October | 39.0 °F | 56.9 °F | 5.22 in. |
| November | 28.8 °F | 44.8 °F | 3.76 in. |
| December | 20.0 °F | 33.7 °F | 3.89 in. |
| Annual | 35.9 °F | 54.2 °F | 46.72 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |