North Berwick, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.8 °C (low) to 14.1 °C (high). Annual precipitation averages 1230.9 Millimeters. North Berwick 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 | -10 °C | 0.4 °C | 88.9 mm |
| February | -9.2 °C | 1.9 °C | 87.38 mm |
| March | -4.4 °C | 6.1 °C | 111.25 mm |
| April | 1.2 °C | 13 °C | 111.76 mm |
| May | 6.8 °C | 19 °C | 94.74 mm |
| June | 12.1 °C | 24.1 °C | 109.47 mm |
| July | 15.3 °C | 27.2 °C | 94.74 mm |
| August | 14.4 °C | 26.6 °C | 90.17 mm |
| September | 10.2 °C | 22.6 °C | 98.55 mm |
| October | 3.9 °C | 15.7 °C | 126.75 mm |
| November | -1.2 °C | 9.4 °C | 102.87 mm |
| December | -6.1 °C | 3.4 °C | 114.3 mm |
| Annual | 2.8 °C | 14.1 °C | 1230.88 mm |
| 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 : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |