York Harbor, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.3 °C (low) to 13.8 °C (high). Annual precipitation averages 1234.5 Millimeters. York Harbor 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 | -7.4 °C | 0.8 °C | 93.98 mm |
| February | -6.9 °C | 2.1 °C | 89.92 mm |
| March | -3 °C | 6.1 °C | 111.51 mm |
| April | 2.2 °C | 12.6 °C | 114.05 mm |
| May | 7.4 °C | 18.2 °C | 96.27 mm |
| June | 12.3 °C | 23.2 °C | 108.2 mm |
| July | 15.7 °C | 26.4 °C | 90.68 mm |
| August | 15.6 °C | 25.9 °C | 86.36 mm |
| September | 12.1 °C | 21.8 °C | 100.08 mm |
| October | 6.4 °C | 15.2 °C | 128.27 mm |
| November | 1.2 °C | 9.4 °C | 100.84 mm |
| December | -3.9 °C | 3.9 °C | 114.3 mm |
| Annual | 4.3 °C | 13.8 °C | 1234.46 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 |