Contoocook, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.5 °F (low) to 57.5 °F (high). Annual precipitation averages 47.2 Inches. Contoocook 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 | 11.5 °F | 31.4 °F | 3.19 in. |
| February | 13.1 °F | 34.6 °F | 3.19 in. |
| March | 21.8 °F | 42.8 °F | 3.64 in. |
| April | 32.7 °F | 56.0 °F | 3.88 in. |
| May | 43.9 °F | 67.9 °F | 3.67 in. |
| June | 53.6 °F | 76.8 °F | 4.4 in. |
| July | 59.1 °F | 82.3 °F | 4.24 in. |
| August | 56.8 °F | 80.7 °F | 3.77 in. |
| September | 49.3 °F | 73.0 °F | 3.84 in. |
| October | 37.5 °F | 59.8 °F | 5.01 in. |
| November | 28.2 °F | 47.9 °F | 3.89 in. |
| December | 18.9 °F | 37.1 °F | 4.48 in. |
| Annual | 35.5 °F | 57.5 °F | 47.2 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 5a : -20°F to -15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |