Berwick, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.9 °C (low) to 14.2 °C (high). Annual precipitation averages 1178.1 Millimeters. Berwick is located in USDA Plant Hardiness Zone 6a. 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 | -9.8 °C | 0.3 °C | 84.33 mm |
| February | -8.9 °C | 1.8 °C | 83.06 mm |
| March | -4.3 °C | 6.1 °C | 105.41 mm |
| April | 1.4 °C | 13.1 °C | 108.46 mm |
| May | 7 °C | 19.1 °C | 91.19 mm |
| June | 12.3 °C | 24.3 °C | 103.38 mm |
| July | 15.4 °C | 27.4 °C | 92.96 mm |
| August | 14.6 °C | 26.8 °C | 87.63 mm |
| September | 10.3 °C | 22.7 °C | 90.42 mm |
| October | 4.1 °C | 15.8 °C | 121.67 mm |
| November | -0.9 °C | 9.3 °C | 98.3 mm |
| December | -5.9 °C | 3.3 °C | 111.25 mm |
| Annual | 2.9 °C | 14.2 °C | 1178.06 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |