Wiscasset, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.3 °F (low) to 55.2 °F (high). Annual precipitation averages 50 Inches. Wiscasset is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 11.9 °F | 30.7 °F | 3.89 in. |
| February | 14.1 °F | 33.7 °F | 3.59 in. |
| March | 23.3 °F | 41.2 °F | 4.37 in. |
| April | 33.3 °F | 52.6 °F | 4.47 in. |
| May | 43.6 °F | 63.7 °F | 3.69 in. |
| June | 52.7 °F | 72.3 °F | 4.5 in. |
| July | 58.8 °F | 78.3 °F | 3.51 in. |
| August | 57.6 °F | 77.5 °F | 3.17 in. |
| September | 50.5 °F | 70.3 °F | 3.97 in. |
| October | 39.9 °F | 58.3 °F | 5.46 in. |
| November | 30.2 °F | 47.2 °F | 4.59 in. |
| December | 19.7 °F | 36.7 °F | 4.83 in. |
| Annual | 36.3 °F | 55.2 °F | 50.04 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |