Warrenton, Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 6.6 °C (low) to 18.9 °C (high). Annual precipitation averages 1141.2 Millimeters. Warrenton 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 | -4.7 °C | 6.7 °C | 77.47 mm |
| February | -3.6 °C | 8.2 °C | 66.04 mm |
| March | 0.1 °C | 12.8 °C | 96.52 mm |
| April | 5.6 °C | 19.1 °C | 90.17 mm |
| May | 10.9 °C | 23.6 °C | 115.57 mm |
| June | 15.8 °C | 28.1 °C | 118.11 mm |
| July | 18.4 °C | 30.4 °C | 110.24 mm |
| August | 17.3 °C | 29.5 °C | 88.14 mm |
| September | 13.5 °C | 26.2 °C | 113.28 mm |
| October | 6.9 °C | 19.9 °C | 93.47 mm |
| November | 1.4 °C | 14 °C | 81.28 mm |
| December | -2.5 °C | 8.7 °C | 90.93 mm |
| Annual | 6.6 °C | 18.9 °C | 1141.22 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 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |