Thomas, West Virginia has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.1 °C (low) to 14.1 °C (high). Annual precipitation averages 1536.2 Millimeters. Thomas is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8 °C | 1.3 °C | 129.29 mm |
| February | -6.9 °C | 3 °C | 116.08 mm |
| March | -3.3 °C | 7.6 °C | 138.18 mm |
| April | 2.2 °C | 14.7 °C | 133.86 mm |
| May | 7.6 °C | 19.2 °C | 153.42 mm |
| June | 11.9 °C | 23.5 °C | 150.11 mm |
| July | 13.8 °C | 25.2 °C | 153.16 mm |
| August | 13 °C | 24.6 °C | 121.41 mm |
| September | 9.7 °C | 21.7 °C | 107.95 mm |
| October | 3.8 °C | 15.7 °C | 102.36 mm |
| November | -1.3 °C | 9.2 °C | 103.89 mm |
| December | -5.2 °C | 3.7 °C | 126.49 mm |
| Annual | 3.1 °C | 14.1 °C | 1536.2 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |