Seabrook Island, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 15.2 °C (low) to 23.7 °C (high). Annual precipitation averages 1300.2 Millimeters. Seabrook Island is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Dec. 1 - Dec. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.6 °C | 14.8 °C | 87.88 mm |
| February | 6.6 °C | 16.2 °C | 84.33 mm |
| March | 9.9 °C | 19.6 °C | 87.38 mm |
| April | 14.2 °C | 23.3 °C | 78.99 mm |
| May | 19.2 °C | 27.1 °C | 75.44 mm |
| June | 22.8 °C | 30.1 °C | 135.64 mm |
| July | 24.5 °C | 31.8 °C | 148.34 mm |
| August | 23.9 °C | 31.1 °C | 177.8 mm |
| September | 22 °C | 29.1 °C | 138.94 mm |
| October | 16.2 °C | 25.1 °C | 115.57 mm |
| November | 10.4 °C | 20.3 °C | 73.91 mm |
| December | 7.1 °C | 16.4 °C | 96.01 mm |
| Annual | 15.2 °C | 23.7 °C | 1300.23 mm |
| Average First Frost Date | Dec. 1 - Dec. 10 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |