Selbyville, Delaware has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.2 °C (low) to 19.2 °C (high). Annual precipitation averages 1248.7 Millimeters. Selbyville 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 Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.8 °C | 7.6 °C | 93.47 mm |
| February | -2.1 °C | 8.8 °C | 81.28 mm |
| March | 1.3 °C | 12.4 °C | 111.25 mm |
| April | 6.7 °C | 18.2 °C | 88.65 mm |
| May | 11.9 °C | 23 °C | 95.5 mm |
| June | 17.2 °C | 27.7 °C | 100.58 mm |
| July | 19.8 °C | 30.6 °C | 118.36 mm |
| August | 18.7 °C | 29.5 °C | 133.35 mm |
| September | 15.4 °C | 26.5 °C | 107.19 mm |
| October | 8.9 °C | 20.8 °C | 118.11 mm |
| November | 3.2 °C | 14.9 °C | 88.39 mm |
| December | -0.4 °C | 10.1 °C | 112.52 mm |
| Annual | 8.2 °C | 19.2 °C | 1248.65 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |