New Wilmington, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 39.4 °F (low) to 60.8 °F (high). Annual precipitation averages 42.6 Inches. New Wilmington 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 Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.5 °F | 35.2 °F | 3.1 in. |
| February | 19.1 °F | 38.2 °F | 2.42 in. |
| March | 26.8 °F | 47.6 °F | 3.12 in. |
| April | 36.9 °F | 61.1 °F | 3.84 in. |
| May | 47.1 °F | 71.4 °F | 3.84 in. |
| June | 56.1 °F | 79.6 °F | 4.56 in. |
| July | 60.1 °F | 83.6 °F | 4.57 in. |
| August | 58.5 °F | 82.3 °F | 3.71 in. |
| September | 51.7 °F | 76.0 °F | 3.94 in. |
| October | 40.9 °F | 63.6 °F | 3.25 in. |
| November | 32.2 °F | 50.7 °F | 3.07 in. |
| December | 24.6 °F | 40.0 °F | 3.2 in. |
| Annual | 39.4 °F | 60.8 °F | 42.62 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 | Dfb - Humid Continental Mild Summer, Wet All Year |