Colebrook, New Hampshire has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from 30.3 °F (low) to 52.5 °F (high). Annual precipitation averages 41.3 Inches. Colebrook is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.4 °F | 24.8 °F | 2.61 in. |
| February | 4.1 °F | 27.7 °F | 1.99 in. |
| March | 14.8 °F | 36.6 °F | 2.49 in. |
| April | 28.3 °F | 50.8 °F | 3.0 in. |
| May | 39.9 °F | 65.1 °F | 4.13 in. |
| June | 49.3 °F | 73.3 °F | 4.54 in. |
| July | 54.3 °F | 77.9 °F | 4.31 in. |
| August | 52.5 °F | 76.7 °F | 4.0 in. |
| September | 44.6 °F | 69.1 °F | 3.43 in. |
| October | 34.6 °F | 55.7 °F | 4.32 in. |
| November | 24.5 °F | 42.0 °F | 3.13 in. |
| December | 12.7 °F | 30.5 °F | 3.31 in. |
| Annual | 30.3 °F | 52.5 °F | 41.26 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 3b : -35°F to -30°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |