Bethany Beach, Delaware has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.7 °C (low) to 17.9 °C (high). Annual precipitation averages 1222 Millimeters. Bethany Beach is located in USDA Plant Hardiness Zone 8a. 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 | -1.5 °C | 6.8 °C | 92.71 mm |
| February | -0.9 °C | 7.7 °C | 78.99 mm |
| March | 2.6 °C | 10.9 °C | 111 mm |
| April | 7.8 °C | 16.4 °C | 89.92 mm |
| May | 13 °C | 21.1 °C | 94.49 mm |
| June | 18.4 °C | 26.1 °C | 96.52 mm |
| July | 21.3 °C | 29 °C | 114.05 mm |
| August | 20.6 °C | 28.1 °C | 122.43 mm |
| September | 17.6 °C | 25.2 °C | 107.19 mm |
| October | 11.2 °C | 19.9 °C | 116.59 mm |
| November | 5.1 °C | 14.1 °C | 89.41 mm |
| December | 1.1 °C | 9.5 °C | 108.71 mm |
| Annual | 9.7 °C | 17.9 °C | 1222.01 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 8a : -12.2°C to -9.4°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 |