Summerville, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.1 °C (low) to 22.3 °C (high). Annual precipitation averages 1463.8 Millimeters. Summerville is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1.2 °C | 10.8 °C | 138.43 mm |
| February | 0.2 °C | 13.2 °C | 141.48 mm |
| March | 3.8 °C | 17.8 °C | 155.7 mm |
| April | 7.9 °C | 22.9 °C | 125.73 mm |
| May | 13.3 °C | 26.8 °C | 116.84 mm |
| June | 17.9 °C | 30.4 °C | 113.28 mm |
| July | 19.9 °C | 32 °C | 106.43 mm |
| August | 19.5 °C | 31.9 °C | 108.2 mm |
| September | 15.9 °C | 29.2 °C | 97.54 mm |
| October | 8.8 °C | 23.4 °C | 96.77 mm |
| November | 2.8 °C | 17.1 °C | 110.24 mm |
| December | 0.3 °C | 12.3 °C | 153.16 mm |
| Annual | 9.1 °C | 22.3 °C | 1463.8 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |