Etna, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.3 °C (low) to 16.8 °C (high). Annual precipitation averages 1052.1 Millimeters. Etna is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.4 °C | 3.1 °C | 83.57 mm |
| February | -4.7 °C | 4.6 °C | 65.53 mm |
| March | -0.9 °C | 9.7 °C | 81.03 mm |
| April | 4.7 °C | 17.2 °C | 88.39 mm |
| May | 10.7 °C | 22.6 °C | 98.81 mm |
| June | 15.7 °C | 27.1 °C | 108.46 mm |
| July | 17.9 °C | 29.3 °C | 107.95 mm |
| August | 17.3 °C | 28.5 °C | 89.15 mm |
| September | 13.4 °C | 24.8 °C | 92.71 mm |
| October | 7.1 °C | 17.9 °C | 78.49 mm |
| November | 1.6 °C | 11.2 °C | 76.2 mm |
| December | -2.4 °C | 5.4 °C | 81.79 mm |
| Annual | 6.3 °C | 16.8 °C | 1052.08 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |