New Castle, Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.2 °C (low) to 19.3 °C (high). Annual precipitation averages 1035.8 Millimeters. New Castle is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.4 °C | 7.2 °C | 79.76 mm |
| February | -2.3 °C | 9.3 °C | 64.01 mm |
| March | 1.3 °C | 13.9 °C | 84.07 mm |
| April | 6.3 °C | 20.3 °C | 87.63 mm |
| May | 11.5 °C | 24.3 °C | 119.13 mm |
| June | 15.7 °C | 28.2 °C | 108.71 mm |
| July | 18.3 °C | 30.1 °C | 99.31 mm |
| August | 17.6 °C | 29.3 °C | 77.22 mm |
| September | 14 °C | 25.9 °C | 83.31 mm |
| October | 7.4 °C | 20.4 °C | 71.63 mm |
| November | 1.6 °C | 14.3 °C | 71.37 mm |
| December | -1.7 °C | 8.9 °C | 89.66 mm |
| Annual | 7.2 °C | 19.3 °C | 1035.81 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |