Rockville, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 58.8 °F (low) to 75 °F (high). Annual precipitation averages 51.9 Inches. Rockville is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Dec. 1 - Dec. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 41.3 °F | 59.0 °F | 3.41 in. |
| February | 43.2 °F | 61.4 °F | 3.26 in. |
| March | 49.3 °F | 67.5 °F | 3.54 in. |
| April | 57.2 °F | 74.4 °F | 3.2 in. |
| May | 65.9 °F | 81.4 °F | 3.08 in. |
| June | 72.6 °F | 86.7 °F | 5.65 in. |
| July | 75.6 °F | 89.7 °F | 6.04 in. |
| August | 74.7 °F | 88.4 °F | 7.26 in. |
| September | 70.8 °F | 84.4 °F | 5.3 in. |
| October | 60.5 °F | 77.2 °F | 4.59 in. |
| November | 49.9 °F | 68.3 °F | 2.82 in. |
| December | 44.1 °F | 61.6 °F | 3.77 in. |
| Annual | 58.8 °F | 75 °F | 51.92 in. |
| Average First Frost Date | Dec. 1 - Dec. 10 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9a : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |