Moultonborough, New Hampshire has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from 1.9 °C (low) to 13.5 °C (high). Annual precipitation averages 1208.8 Millimeters. Moultonborough 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.5 °C | -1.3 °C | 80.77 mm |
| February | -11.1 °C | 0.3 °C | 78.74 mm |
| March | -6.2 °C | 5.3 °C | 90.93 mm |
| April | 0.2 °C | 12.9 °C | 95.76 mm |
| May | 6.5 °C | 20.1 °C | 99.82 mm |
| June | 11.8 °C | 24.6 °C | 109.73 mm |
| July | 14.7 °C | 27.4 °C | 118.11 mm |
| August | 13.8 °C | 26.6 °C | 99.31 mm |
| September | 9.6 °C | 22.1 °C | 96.77 mm |
| October | 3.6 °C | 14.7 °C | 131.83 mm |
| November | -1.6 °C | 7.8 °C | 95.76 mm |
| December | -7 °C | 1.8 °C | 111.25 mm |
| Annual | 1.9 °C | 13.5 °C | 1208.78 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Normal |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |