Big Rock, Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7 °C (low) to 19.6 °C (high). Annual precipitation averages 1187.7 Millimeters. Big Rock is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.7 °C | 7.1 °C | 87.63 mm |
| February | -2.6 °C | 9.3 °C | 86.36 mm |
| March | 0.7 °C | 14.4 °C | 109.22 mm |
| April | 6.1 °C | 20.9 °C | 104.65 mm |
| May | 11 °C | 24.7 °C | 118.11 mm |
| June | 16.1 °C | 28.2 °C | 117.09 mm |
| July | 17.9 °C | 29.9 °C | 142.49 mm |
| August | 17.5 °C | 29.3 °C | 99.31 mm |
| September | 14.1 °C | 26.6 °C | 82.8 mm |
| October | 7.2 °C | 20.7 °C | 71.37 mm |
| November | 1.3 °C | 14.4 °C | 69.09 mm |
| December | -1.3 °C | 9.1 °C | 99.57 mm |
| Annual | 7 °C | 19.6 °C | 1187.69 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |