Kiawah Island, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 15.1 °C (low) to 23.6 °C (high). Annual precipitation averages 1314.7 Millimeters. Kiawah 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. 11 - Dec. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.4 °C | 14.8 °C | 86.87 mm |
| February | 6.3 °C | 16.2 °C | 84.58 mm |
| March | 9.9 °C | 19.4 °C | 87.63 mm |
| April | 14.2 °C | 23.2 °C | 79.5 mm |
| May | 19.2 °C | 27.1 °C | 78.49 mm |
| June | 22.8 °C | 29.9 °C | 138.18 mm |
| July | 24.4 °C | 31.7 °C | 156.21 mm |
| August | 23.9 °C | 31 °C | 177.04 mm |
| September | 21.8 °C | 28.9 °C | 143 mm |
| October | 16.2 °C | 24.8 °C | 116.33 mm |
| November | 10.4 °C | 20.1 °C | 73.15 mm |
| December | 6.9 °C | 16.3 °C | 93.73 mm |
| Annual | 15.1 °C | 23.6 °C | 1314.71 mm |
| Average First Frost Date | Dec. 11 - Dec. 20 |
| 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 |