Islandton, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.4 °C (low) to 24.9 °C (high). Annual precipitation averages 1268.2 Millimeters. Islandton is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.6 °C | 15.6 °C | 96.77 mm |
| February | 4 °C | 17.4 °C | 93.98 mm |
| March | 7.3 °C | 21.2 °C | 94.74 mm |
| April | 11.3 °C | 25.2 °C | 82.55 mm |
| May | 16.1 °C | 28.9 °C | 86.61 mm |
| June | 20.2 °C | 31.9 °C | 145.03 mm |
| July | 22 °C | 33.3 °C | 144.27 mm |
| August | 21.8 °C | 32.4 °C | 151.13 mm |
| September | 19.1 °C | 29.9 °C | 118.87 mm |
| October | 12.9 °C | 25.6 °C | 86.61 mm |
| November | 7 °C | 20.6 °C | 72.14 mm |
| December | 4.1 °C | 16.8 °C | 95.5 mm |
| Annual | 12.4 °C | 24.9 °C | 1268.2 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°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 |