Westminster, South Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10 °C (low) to 22.4 °C (high). Annual precipitation averages 1429.2 Millimeters. Westminster 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 | -0.1 °C | 11.7 °C | 129.54 mm |
| February | 1.3 °C | 13.8 °C | 119.63 mm |
| March | 4.7 °C | 17.9 °C | 127.76 mm |
| April | 9.1 °C | 23.1 °C | 109.47 mm |
| May | 14 °C | 26.8 °C | 104.14 mm |
| June | 18.4 °C | 30.3 °C | 123.19 mm |
| July | 20.3 °C | 32.1 °C | 114.55 mm |
| August | 19.9 °C | 31.3 °C | 142.49 mm |
| September | 16.8 °C | 28.4 °C | 107.7 mm |
| October | 10.2 °C | 23.1 °C | 107.44 mm |
| November | 4.3 °C | 17.6 °C | 107.44 mm |
| December | 1.4 °C | 13 °C | 135.89 mm |
| Annual | 10 °C | 22.4 °C | 1429.24 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 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 | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |