South Bethany, Delaware has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.8 °C (low) to 17.7 °C (high). Annual precipitation averages 1229.4 Millimeters. South Bethany 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 | -1.3 °C | 6.7 °C | 93.73 mm |
| February | -0.8 °C | 7.4 °C | 78.99 mm |
| March | 2.7 °C | 10.4 °C | 111.76 mm |
| April | 7.8 °C | 16.1 °C | 90.68 mm |
| May | 12.9 °C | 20.7 °C | 95.25 mm |
| June | 18.2 °C | 25.8 °C | 96.52 mm |
| July | 21.3 °C | 28.7 °C | 114.05 mm |
| August | 20.8 °C | 27.9 °C | 123.44 mm |
| September | 17.9 °C | 25.1 °C | 107.7 mm |
| October | 11.4 °C | 19.9 °C | 117.86 mm |
| November | 5.4 °C | 14 °C | 90.17 mm |
| December | 1.2 °C | 9.4 °C | 109.22 mm |
| Annual | 9.8 °C | 17.7 °C | 1229.37 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 |