Exton, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.9 °F (low) to 63.3 °F (high). Annual precipitation averages 49.2 Inches. Exton 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 21.9 °F | 39.4 °F | 3.57 in. |
| February | 22.8 °F | 41.8 °F | 2.93 in. |
| March | 30.1 °F | 50.5 °F | 4.24 in. |
| April | 40.5 °F | 63.0 °F | 3.8 in. |
| May | 50.3 °F | 72.5 °F | 3.94 in. |
| June | 59.7 °F | 81.3 °F | 4.52 in. |
| July | 65.0 °F | 85.6 °F | 4.66 in. |
| August | 63.3 °F | 84.2 °F | 4.37 in. |
| September | 55.8 °F | 77.8 °F | 5.07 in. |
| October | 44.1 °F | 65.7 °F | 4.41 in. |
| November | 34.2 °F | 54.1 °F | 3.33 in. |
| December | 27.3 °F | 43.9 °F | 4.33 in. |
| Annual | 42.9 °F | 63.3 °F | 49.17 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 6b : -5°F to 0°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |