Sanbornville, 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 56.1 °F (high). Annual precipitation averages 49.4 Inches. Sanbornville is located in USDA Plant Hardiness Zone 5b. 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 | 12.4 °F | 29.6 °F | 3.4 in. |
| February | 13.4 °F | 32.5 °F | 3.75 in. |
| March | 21.7 °F | 41.3 °F | 3.99 in. |
| April | 33.0 °F | 54.9 °F | 4.12 in. |
| May | 43.8 °F | 67.6 °F | 3.7 in. |
| June | 53.3 °F | 76.2 °F | 4.4 in. |
| July | 58.7 °F | 81.1 °F | 4.23 in. |
| August | 57.3 °F | 79.4 °F | 3.93 in. |
| September | 49.6 °F | 71.4 °F | 3.8 in. |
| October | 38.9 °F | 57.9 °F | 5.05 in. |
| November | 29.2 °F | 45.7 °F | 4.21 in. |
| December | 19.7 °F | 35.2 °F | 4.8 in. |
| Annual | 35.9 °F | 56.1 °F | 49.38 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 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |