Alcolu, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.4 °C (low) to 24.2 °C (high). Annual precipitation averages 1290.8 Millimeters. Alcolu 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. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.4 °C | 14.1 °C | 104.65 mm |
| February | 2.7 °C | 16 °C | 100.08 mm |
| March | 5.9 °C | 20.1 °C | 97.54 mm |
| April | 10.6 °C | 24.8 °C | 93.22 mm |
| May | 15.3 °C | 28.6 °C | 96.77 mm |
| June | 19.8 °C | 31.7 °C | 134.11 mm |
| July | 21.8 °C | 33.3 °C | 132.59 mm |
| August | 21.1 °C | 32.4 °C | 146.05 mm |
| September | 18 °C | 29.5 °C | 125.73 mm |
| October | 11.7 °C | 24.7 °C | 90.68 mm |
| November | 5.7 °C | 19.6 °C | 71.63 mm |
| December | 2.8 °C | 15.5 °C | 97.79 mm |
| Annual | 11.4 °C | 24.2 °C | 1290.84 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |