Seaford, Delaware has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.8 °C (low) to 19 °C (high). Annual precipitation averages 1194.1 Millimeters. Seaford is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.5 °C | 6.8 °C | 87.38 mm |
| February | -2.8 °C | 8.3 °C | 76.2 mm |
| March | 0.6 °C | 12.2 °C | 105.66 mm |
| April | 6.4 °C | 18.2 °C | 90.42 mm |
| May | 12 °C | 23.3 °C | 97.54 mm |
| June | 17.2 °C | 28.3 °C | 105.92 mm |
| July | 19.8 °C | 30.6 °C | 111 mm |
| August | 18.5 °C | 29.4 °C | 121.16 mm |
| September | 15.1 °C | 26.4 °C | 114.55 mm |
| October | 8.6 °C | 20.6 °C | 103.38 mm |
| November | 2.5 °C | 14.5 °C | 83.57 mm |
| December | -1 °C | 9.4 °C | 97.28 mm |
| Annual | 7.8 °C | 19 °C | 1194.06 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |