Wilmington, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.8 °C (low) to 12.3 °C (high). Annual precipitation averages 1037.6 Millimeters. Wilmington is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -13.7 °C | -2.8 °C | 67.31 mm |
| February | -12.8 °C | -1.1 °C | 55.37 mm |
| March | -7.6 °C | 3.8 °C | 72.64 mm |
| April | -0.4 °C | 11.6 °C | 81.28 mm |
| May | 6.1 °C | 18.9 °C | 91.95 mm |
| June | 11.3 °C | 23.7 °C | 114.3 mm |
| July | 14 °C | 26.2 °C | 102.87 mm |
| August | 13 °C | 25.3 °C | 101.35 mm |
| September | 8.7 °C | 21.4 °C | 90.42 mm |
| October | 2.8 °C | 13.7 °C | 105.66 mm |
| November | -2.8 °C | 6.6 °C | 78.99 mm |
| December | -9.1 °C | 0.3 °C | 75.44 mm |
| Annual | 0.8 °C | 12.3 °C | 1037.58 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |