Boscawen, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35 °F (low) to 56.8 °F (high). Annual precipitation averages 48.3 Inches. Boscawen 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 | 30.6 °F | 3.28 in. |
| February | 12.9 °F | 33.9 °F | 3.25 in. |
| March | 20.9 °F | 42.1 °F | 3.75 in. |
| April | 32.1 °F | 55.5 °F | 3.93 in. |
| May | 43.4 °F | 67.6 °F | 3.69 in. |
| June | 52.8 °F | 76.2 °F | 4.39 in. |
| July | 58.2 °F | 81.5 °F | 4.54 in. |
| August | 56.1 °F | 79.8 °F | 3.85 in. |
| September | 48.5 °F | 72.3 °F | 3.78 in. |
| October | 37.0 °F | 59.0 °F | 5.11 in. |
| November | 28.0 °F | 47.0 °F | 4.04 in. |
| December | 18.6 °F | 36.0 °F | 4.65 in. |
| Annual | 35 °F | 56.8 °F | 48.26 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 5b : -15°F to -10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |