Kennebunkport, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4 °C (low) to 13.1 °C (high). Annual precipitation averages 1294.4 Millimeters. Kennebunkport is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.1 °C | 0.6 °C | 92.96 mm |
| February | -7.6 °C | 1.8 °C | 93.47 mm |
| March | -3.3 °C | 5.4 °C | 117.09 mm |
| April | 1.9 °C | 11.3 °C | 118.87 mm |
| May | 7.2 °C | 16.8 °C | 100.33 mm |
| June | 12.4 °C | 22.1 °C | 112.52 mm |
| July | 15.7 °C | 25.2 °C | 96.01 mm |
| August | 15.3 °C | 24.8 °C | 96.77 mm |
| September | 11.8 °C | 21.1 °C | 99.82 mm |
| October | 6 °C | 14.9 °C | 140.72 mm |
| November | 0.8 °C | 9.2 °C | 105.92 mm |
| December | -4.3 °C | 3.8 °C | 119.89 mm |
| Annual | 4 °C | 13.1 °C | 1294.37 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| 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 |