Plaistow, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.6 °F (low) to 59.3 °F (high). Annual precipitation averages 47.9 Inches. Plaistow 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.0 °F | 34.9 °F | 3.5 in. |
| February | 17.7 °F | 37.6 °F | 3.44 in. |
| March | 25.3 °F | 45.1 °F | 4.53 in. |
| April | 35.6 °F | 57.7 °F | 4.16 in. |
| May | 45.9 °F | 68.1 °F | 3.84 in. |
| June | 55.4 °F | 77.1 °F | 4.24 in. |
| July | 61.3 °F | 82.9 °F | 3.57 in. |
| August | 59.6 °F | 81.4 °F | 3.52 in. |
| September | 52.0 °F | 74.1 °F | 3.84 in. |
| October | 40.3 °F | 61.8 °F | 4.92 in. |
| November | 31.2 °F | 50.7 °F | 3.83 in. |
| December | 22.5 °F | 40.2 °F | 4.54 in. |
| Annual | 38.6 °F | 59.3 °F | 47.93 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 6a : -10°F to -5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |