Winterstown, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.6 °F (low) to 63.5 °F (high). Annual precipitation averages 46.7 Inches. Winterstown is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.3 °F | 39.6 °F | 3.33 in. |
| February | 24.9 °F | 42.9 °F | 2.76 in. |
| March | 31.3 °F | 51.6 °F | 4.1 in. |
| April | 41.8 °F | 64.0 °F | 3.67 in. |
| May | 51.1 °F | 73.2 °F | 4.08 in. |
| June | 60.0 °F | 80.8 °F | 4.12 in. |
| July | 64.4 °F | 85.1 °F | 4.48 in. |
| August | 62.3 °F | 83.5 °F | 4.1 in. |
| September | 56.0 °F | 77.3 °F | 4.9 in. |
| October | 44.7 °F | 65.8 °F | 4.19 in. |
| November | 35.4 °F | 54.4 °F | 3.24 in. |
| December | 28.0 °F | 43.8 °F | 3.74 in. |
| Annual | 43.6 °F | 63.5 °F | 46.71 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 |