Etna, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.2 °F (low) to 54.1 °F (high). Annual precipitation averages 45.6 Inches. Etna is located in USDA Plant Hardiness Zone 5a. 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 | 6.8 °F | 26.8 °F | 3.44 in. |
| February | 8.2 °F | 30.3 °F | 2.91 in. |
| March | 18.8 °F | 39.0 °F | 3.63 in. |
| April | 30.8 °F | 52.2 °F | 3.9 in. |
| May | 41.8 °F | 65.0 °F | 3.59 in. |
| June | 51.5 °F | 73.7 °F | 4.17 in. |
| July | 57.3 °F | 79.2 °F | 3.38 in. |
| August | 55.4 °F | 78.1 °F | 3.5 in. |
| September | 47.4 °F | 70.4 °F | 3.73 in. |
| October | 36.7 °F | 57.1 °F | 4.91 in. |
| November | 27.4 °F | 44.4 °F | 4.15 in. |
| December | 15.8 °F | 33.0 °F | 4.29 in. |
| Annual | 33.2 °F | 54.1 °F | 45.6 in. |
| 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |