King William, Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.8 °C (low) to 21 °C (high). Annual precipitation averages 1178 Millimeters. King William is located in USDA Plant Hardiness Zone 7b. 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 | -2.1 °C | 9.2 °C | 82.8 mm |
| February | -1.3 °C | 11.1 °C | 71.88 mm |
| March | 2.4 °C | 15.4 °C | 102.36 mm |
| April | 7.8 °C | 21.6 °C | 85.85 mm |
| May | 13.2 °C | 25.4 °C | 100.33 mm |
| June | 17.9 °C | 29.6 °C | 108.46 mm |
| July | 20.3 °C | 31.8 °C | 125.22 mm |
| August | 19.4 °C | 30.7 °C | 119.89 mm |
| September | 15.9 °C | 27.6 °C | 113.79 mm |
| October | 9.1 °C | 22 °C | 96.52 mm |
| November | 3.3 °C | 16.1 °C | 81.79 mm |
| December | -0.2 °C | 11.1 °C | 89.15 mm |
| Annual | 8.8 °C | 21 °C | 1178.04 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |