Johnsonville, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.3 °C (low) to 23.7 °C (high). Annual precipitation averages 1304 Millimeters. Johnsonville 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. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.3 °C | 13.9 °C | 93.98 mm |
| February | 2.5 °C | 15.7 °C | 87.12 mm |
| March | 5.7 °C | 19.6 °C | 92.46 mm |
| April | 10.3 °C | 24.3 °C | 85.85 mm |
| May | 15.2 °C | 27.9 °C | 94.23 mm |
| June | 19.8 °C | 31 °C | 122.43 mm |
| July | 21.7 °C | 32.5 °C | 137.16 mm |
| August | 21.1 °C | 31.7 °C | 157.73 mm |
| September | 18 °C | 28.8 °C | 154.18 mm |
| October | 11.5 °C | 24.5 °C | 103.38 mm |
| November | 5.6 °C | 19.4 °C | 80.52 mm |
| December | 2.8 °C | 15.3 °C | 95 mm |
| Annual | 11.3 °C | 23.7 °C | 1304.04 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| 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 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |