Londonderry, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.9 °F (low) to 58.3 °F (high). Annual precipitation averages 46.8 Inches. Londonderry is located in USDA Plant Hardiness Zone 6a. 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 | 15.4 °F | 33.5 °F | 3.24 in. |
| February | 17.0 °F | 35.9 °F | 3.23 in. |
| March | 24.5 °F | 43.9 °F | 4.04 in. |
| April | 35.5 °F | 56.9 °F | 3.98 in. |
| May | 45.4 °F | 67.9 °F | 3.76 in. |
| June | 54.9 °F | 76.7 °F | 4.25 in. |
| July | 60.2 °F | 82.1 °F | 3.68 in. |
| August | 58.2 °F | 80.7 °F | 3.76 in. |
| September | 51.0 °F | 73.5 °F | 3.93 in. |
| October | 40.0 °F | 60.4 °F | 4.8 in. |
| November | 31.1 °F | 49.7 °F | 3.84 in. |
| December | 21.6 °F | 38.4 °F | 4.29 in. |
| Annual | 37.9 °F | 58.3 °F | 46.8 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 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 |