Montross, Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.9 °C (low) to 20.4 °C (high). Annual precipitation averages 1161.8 Millimeters. Montross 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 | -2.2 °C | 8.2 °C | 80.77 mm |
| February | -1.5 °C | 9.8 °C | 69.85 mm |
| March | 2.2 °C | 14.4 °C | 97.03 mm |
| April | 7.6 °C | 20.7 °C | 83.82 mm |
| May | 12.9 °C | 25.1 °C | 103.12 mm |
| June | 17.8 °C | 29.4 °C | 112.78 mm |
| July | 20.4 °C | 31.7 °C | 115.82 mm |
| August | 19.5 °C | 30.6 °C | 114.05 mm |
| September | 16 °C | 27.3 °C | 108.71 mm |
| October | 9.7 °C | 21.6 °C | 102.87 mm |
| November | 3.8 °C | 15.4 °C | 82.8 mm |
| December | 0.1 °C | 10.3 °C | 90.17 mm |
| Annual | 8.9 °C | 20.4 °C | 1161.79 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |