Seabrook, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 43.9 °F (low) to 58.6 °F (high). Annual precipitation averages 49.7 Inches. Seabrook is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.9 °F | 39.0 °F | 4.22 in. |
| February | 24.8 °F | 39.9 °F | 3.72 in. |
| March | 30.5 °F | 45.1 °F | 5.18 in. |
| April | 39.3 °F | 53.7 °F | 4.4 in. |
| May | 48.5 °F | 63.2 °F | 3.52 in. |
| June | 57.9 °F | 72.3 °F | 3.72 in. |
| July | 64.8 °F | 78.8 °F | 2.99 in. |
| August | 64.2 °F | 78.3 °F | 3.68 in. |
| September | 57.7 °F | 72.5 °F | 4.06 in. |
| October | 47.3 °F | 62.5 °F | 4.79 in. |
| November | 38.2 °F | 53.3 °F | 4.18 in. |
| December | 30.0 °F | 44.7 °F | 5.21 in. |
| Annual | 43.9 °F | 58.6 °F | 49.67 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |