Donegal, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38.7 °F (low) to 58.5 °F (high). Annual precipitation averages 48.1 Inches. Donegal is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.1 °F | 34.3 °F | 3.74 in. |
| February | 19.4 °F | 37.1 °F | 3.46 in. |
| March | 26.0 °F | 45.8 °F | 4.07 in. |
| April | 36.7 °F | 59.2 °F | 4.09 in. |
| May | 46.4 °F | 68.9 °F | 4.52 in. |
| June | 55.1 °F | 76.3 °F | 4.96 in. |
| July | 59.6 °F | 80.1 °F | 4.47 in. |
| August | 57.8 °F | 79.1 °F | 4.14 in. |
| September | 51.0 °F | 72.8 °F | 3.69 in. |
| October | 40.2 °F | 61.2 °F | 3.58 in. |
| November | 30.8 °F | 48.7 °F | 3.57 in. |
| December | 23.6 °F | 38.6 °F | 3.76 in. |
| Annual | 38.7 °F | 58.5 °F | 48.05 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |