Summerville, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.3 °C (low) to 24.4 °C (high). Annual precipitation averages 1364 Millimeters. Summerville is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Feb. 11 - Feb. 20 through the first frost around Dec. 11 - Dec. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.3 °C | 15.1 °C | 93.73 mm |
| February | 3.7 °C | 17.1 °C | 88.14 mm |
| March | 6.8 °C | 20.6 °C | 95.5 mm |
| April | 11.2 °C | 24.7 °C | 87.38 mm |
| May | 16.1 °C | 28.3 °C | 92.46 mm |
| June | 20.4 °C | 31.3 °C | 156.97 mm |
| July | 22.2 °C | 32.9 °C | 170.18 mm |
| August | 21.8 °C | 32 °C | 161.29 mm |
| September | 19.2 °C | 29.5 °C | 145.54 mm |
| October | 12.9 °C | 25.1 °C | 106.17 mm |
| November | 6.9 °C | 20.2 °C | 73.15 mm |
| December | 3.9 °C | 16.3 °C | 93.47 mm |
| Annual | 12.3 °C | 24.4 °C | 1363.98 mm |
| Average First Frost Date | Dec. 11 - Dec. 20 |
| Average Last Frost Date | Feb. 11 - Feb. 20 |
| Average Days With Frost | 10-20 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |