Downingtown, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.8 °F (low) to 63.9 °F (high). Annual precipitation averages 49.6 Inches. Downingtown is located in USDA Plant Hardiness Zone 7a. 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 | 20.7 °F | 40.0 °F | 3.6 in. |
| February | 21.6 °F | 42.3 °F | 2.97 in. |
| March | 29.1 °F | 50.9 °F | 4.3 in. |
| April | 39.5 °F | 63.6 °F | 3.82 in. |
| May | 49.5 °F | 73.1 °F | 3.95 in. |
| June | 59.0 °F | 81.8 °F | 4.55 in. |
| July | 64.0 °F | 86.1 °F | 4.66 in. |
| August | 62.2 °F | 84.8 °F | 4.41 in. |
| September | 54.5 °F | 78.3 °F | 5.05 in. |
| October | 42.6 °F | 66.4 °F | 4.57 in. |
| November | 32.4 °F | 54.6 °F | 3.38 in. |
| December | 26.3 °F | 44.4 °F | 4.34 in. |
| Annual | 41.8 °F | 63.9 °F | 49.6 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |