Northwood, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.5 °F (low) to 57.5 °F (high). Annual precipitation averages 46.8 Inches. Northwood is located in USDA Plant Hardiness Zone 6a. 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 | 15.6 °F | 31.6 °F | 3.3 in. |
| February | 16.1 °F | 34.8 °F | 3.13 in. |
| March | 24.3 °F | 42.3 °F | 3.76 in. |
| April | 33.9 °F | 56.4 °F | 3.82 in. |
| May | 44.5 °F | 67.6 °F | 4.0 in. |
| June | 54.8 °F | 76.7 °F | 4.39 in. |
| July | 59.5 °F | 82.1 °F | 3.94 in. |
| August | 58.8 °F | 80.4 °F | 4.02 in. |
| September | 50.2 °F | 73.3 °F | 3.76 in. |
| October | 40.9 °F | 60.1 °F | 4.77 in. |
| November | 30.1 °F | 47.6 °F | 3.68 in. |
| December | 20.9 °F | 37.1 °F | 4.24 in. |
| Annual | 37.5 °F | 57.5 °F | 46.81 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 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |