Northeast Harbor, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.8 °F (low) to 53.6 °F (high). Annual precipitation averages 54 Inches. Northeast Harbor is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.0 °F | 31.4 °F | 4.67 in. |
| February | 19.7 °F | 32.9 °F | 3.89 in. |
| March | 25.4 °F | 39.3 °F | 4.8 in. |
| April | 34.5 °F | 49.9 °F | 4.56 in. |
| May | 43.5 °F | 60.4 °F | 4.43 in. |
| June | 52.0 °F | 69.7 °F | 4.25 in. |
| July | 58.0 °F | 75.5 °F | 3.24 in. |
| August | 57.7 °F | 75.1 °F | 3.05 in. |
| September | 51.9 °F | 68.0 °F | 4.12 in. |
| October | 43.8 °F | 57.0 °F | 5.71 in. |
| November | 35.1 °F | 46.8 °F | 5.63 in. |
| December | 25.5 °F | 37.4 °F | 5.6 in. |
| Annual | 38.8 °F | 53.6 °F | 53.95 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |