Plum Branch, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.7 °C (low) to 23.7 °C (high). Annual precipitation averages 1175.3 Millimeters. Plum Branch is located in USDA Plant Hardiness Zone 8b. 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 | 0.7 °C | 13 °C | 103.12 mm |
| February | 1.8 °C | 14.9 °C | 98.3 mm |
| March | 5.2 °C | 19.3 °C | 114.55 mm |
| April | 9.7 °C | 24 °C | 80.52 mm |
| May | 14.6 °C | 28.1 °C | 82.3 mm |
| June | 19.1 °C | 31.5 °C | 116.33 mm |
| July | 21.1 °C | 33.3 °C | 104.14 mm |
| August | 20.6 °C | 32.6 °C | 110.49 mm |
| September | 17.3 °C | 29.7 °C | 93.22 mm |
| October | 10.9 °C | 24.6 °C | 76.2 mm |
| November | 4.8 °C | 18.7 °C | 87.88 mm |
| December | 2.1 °C | 14.2 °C | 108.2 mm |
| Annual | 10.7 °C | 23.7 °C | 1175.25 mm |
| 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 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |