Jefferson, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 50.9 °F (low) to 73.8 °F (high). Annual precipitation averages 46.4 Inches. Jefferson 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 Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 32.2 °F | 54.4 °F | 3.96 in. |
| February | 34.4 °F | 58.0 °F | 3.33 in. |
| March | 40.8 °F | 65.7 °F | 3.86 in. |
| April | 49.5 °F | 75.0 °F | 3.47 in. |
| May | 58.4 °F | 81.8 °F | 3.28 in. |
| June | 66.4 °F | 88.6 °F | 4.37 in. |
| July | 70.1 °F | 91.5 °F | 4.5 in. |
| August | 69.0 °F | 89.7 °F | 4.53 in. |
| September | 63.1 °F | 84.4 °F | 4.35 in. |
| October | 51.0 °F | 75.0 °F | 3.46 in. |
| November | 40.5 °F | 64.9 °F | 3.34 in. |
| December | 35.1 °F | 57.1 °F | 3.9 in. |
| Annual | 50.9 °F | 73.8 °F | 46.35 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : 10°F to 15°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |