Castlewood, Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 42.8 °F (low) to 68.4 °F (high). Annual precipitation averages 45.6 Inches. Castlewood is located in USDA Plant Hardiness Zone 7a. 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 | 24.0 °F | 46.0 °F | 3.46 in. |
| February | 26.2 °F | 49.9 °F | 3.35 in. |
| March | 33.0 °F | 58.8 °F | 4.16 in. |
| April | 40.9 °F | 70.3 °F | 4.03 in. |
| May | 50.3 °F | 77.9 °F | 4.18 in. |
| June | 58.5 °F | 84.2 °F | 4.58 in. |
| July | 62.7 °F | 87.0 °F | 4.99 in. |
| August | 61.6 °F | 85.9 °F | 4.21 in. |
| September | 54.8 °F | 81.6 °F | 3.46 in. |
| October | 42.0 °F | 71.2 °F | 2.74 in. |
| November | 32.1 °F | 58.8 °F | 2.73 in. |
| December | 27.3 °F | 49.2 °F | 3.66 in. |
| Annual | 42.8 °F | 68.4 °F | 45.55 in. |
| 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 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |