Kennebunk, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.6 °C (low) to 13.4 °C (high). Annual precipitation averages 1269.2 Millimeters. Kennebunk 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 | -9.3 °C | 0.5 °C | 91.95 mm |
| February | -8.4 °C | 1.7 °C | 91.69 mm |
| March | -3.8 °C | 5.7 °C | 115.57 mm |
| April | 1.8 °C | 12 °C | 115.32 mm |
| May | 7.4 °C | 17.8 °C | 96.77 mm |
| June | 12.8 °C | 22.6 °C | 111.76 mm |
| July | 16.1 °C | 25.7 °C | 91.95 mm |
| August | 15.4 °C | 25.3 °C | 92.96 mm |
| September | 11.3 °C | 21.6 °C | 99.57 mm |
| October | 5.1 °C | 15.1 °C | 136.14 mm |
| November | -0.2 °C | 9.3 °C | 107.19 mm |
| December | -5.3 °C | 3.7 °C | 118.36 mm |
| Annual | 3.6 °C | 13.4 °C | 1269.23 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 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 |