Cornwells Heights, Pennsylvania has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.7 °C (low) to 18.1 °C (high). Annual precipitation averages 1213.4 Millimeters. Cornwells Heights is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.9 °C | 5 °C | 90.17 mm |
| February | -3.3 °C | 6.5 °C | 70.36 mm |
| March | 0.7 °C | 10.9 °C | 113.03 mm |
| April | 6.2 °C | 17.6 °C | 90.42 mm |
| May | 11.6 °C | 22.8 °C | 102.87 mm |
| June | 16.8 °C | 27.9 °C | 107.95 mm |
| July | 19.9 °C | 30.4 °C | 119.38 mm |
| August | 19.1 °C | 29.6 °C | 123.7 mm |
| September | 14.9 °C | 26.1 °C | 104.39 mm |
| October | 8.6 °C | 19.3 °C | 99.57 mm |
| November | 2.9 °C | 13.3 °C | 81.03 mm |
| December | -1.2 °C | 7.6 °C | 110.49 mm |
| Annual | 7.7 °C | 18.1 °C | 1213.36 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |