Walpole, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.2 °F (low) to 57.1 °F (high). Annual precipitation averages 44 Inches. Walpole is located in USDA Plant Hardiness Zone 5b. 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 | 10.9 °F | 30.8 °F | 3.08 in. |
| February | 12.2 °F | 34.1 °F | 2.48 in. |
| March | 21.2 °F | 42.3 °F | 3.26 in. |
| April | 32.6 °F | 55.4 °F | 3.29 in. |
| May | 43.9 °F | 67.8 °F | 3.64 in. |
| June | 53.4 °F | 76.5 °F | 4.17 in. |
| July | 58.6 °F | 81.7 °F | 4.1 in. |
| August | 56.6 °F | 80.3 °F | 4.0 in. |
| September | 48.8 °F | 73.0 °F | 4.04 in. |
| October | 37.1 °F | 59.7 °F | 4.78 in. |
| November | 28.2 °F | 47.3 °F | 3.46 in. |
| December | 18.6 °F | 35.8 °F | 3.7 in. |
| Annual | 35.2 °F | 57.1 °F | 44 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°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 |