Yarmouth, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.9 °F (low) to 55.8 °F (high). Annual precipitation averages 50 Inches. Yarmouth 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.7 °F | 31.6 °F | 3.55 in. |
| February | 15.4 °F | 34.4 °F | 3.55 in. |
| March | 24.7 °F | 41.8 °F | 4.05 in. |
| April | 34.9 °F | 53.1 °F | 4.59 in. |
| May | 45.2 °F | 63.8 °F | 3.64 in. |
| June | 54.5 °F | 72.6 °F | 4.62 in. |
| July | 60.7 °F | 78.6 °F | 3.68 in. |
| August | 59.7 °F | 78.3 °F | 3.53 in. |
| September | 52.2 °F | 71.1 °F | 4.0 in. |
| October | 41.3 °F | 59.0 °F | 5.64 in. |
| November | 31.5 °F | 47.9 °F | 4.44 in. |
| December | 21.3 °F | 37.7 °F | 4.72 in. |
| Annual | 37.9 °F | 55.8 °F | 50.01 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |