Sanbornville, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.2 °C (low) to 13.4 °C (high). Annual precipitation averages 1254.3 Millimeters. 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 | -10.9 °C | -1.3 °C | 86.36 mm |
| February | -10.3 °C | 0.3 °C | 95.25 mm |
| March | -5.7 °C | 5.2 °C | 101.35 mm |
| April | 0.6 °C | 12.7 °C | 104.65 mm |
| May | 6.6 °C | 19.8 °C | 93.98 mm |
| June | 11.8 °C | 24.6 °C | 111.76 mm |
| July | 14.8 °C | 27.3 °C | 107.44 mm |
| August | 14.1 °C | 26.3 °C | 99.82 mm |
| September | 9.8 °C | 21.9 °C | 96.52 mm |
| October | 3.8 °C | 14.4 °C | 128.27 mm |
| November | -1.6 °C | 7.6 °C | 106.93 mm |
| December | -6.8 °C | 1.8 °C | 121.92 mm |
| Annual | 2.2 °C | 13.4 °C | 1254.25 mm |
| 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 : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |