West Union, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.7 °C (low) to 22.4 °C (high). Annual precipitation averages 1525 Millimeters. West Union is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -0.6 °C | 11.7 °C | 134.87 mm |
| February | 0.9 °C | 13.8 °C | 121.67 mm |
| March | 4.3 °C | 17.9 °C | 132.33 mm |
| April | 8.7 °C | 23 °C | 117.35 mm |
| May | 13.6 °C | 26.7 °C | 113.28 mm |
| June | 18.2 °C | 30.3 °C | 131.32 mm |
| July | 20.1 °C | 32 °C | 124.21 mm |
| August | 19.7 °C | 31.2 °C | 159.51 mm |
| September | 16.5 °C | 28.3 °C | 117.86 mm |
| October | 9.7 °C | 22.9 °C | 114.3 mm |
| November | 3.9 °C | 17.6 °C | 113.54 mm |
| December | 1 °C | 12.9 °C | 144.78 mm |
| Annual | 9.7 °C | 22.4 °C | 1525.02 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |