Smithers, West Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 6.8 °C (low) to 18.8 °C (high). Annual precipitation averages 1199.4 Millimeters. Smithers is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.2 °C | 6 °C | 81.79 mm |
| February | -3.1 °C | 8.1 °C | 77.98 mm |
| March | 0.3 °C | 13.1 °C | 109.73 mm |
| April | 5.7 °C | 19.9 °C | 97.03 mm |
| May | 11 °C | 23.9 °C | 125.98 mm |
| June | 15.8 °C | 27.8 °C | 116.08 mm |
| July | 18 °C | 29.5 °C | 147.07 mm |
| August | 17.4 °C | 29 °C | 103.89 mm |
| September | 13.7 °C | 26.1 °C | 89.41 mm |
| October | 7.1 °C | 20.1 °C | 77.98 mm |
| November | 1.3 °C | 13.7 °C | 76.45 mm |
| December | -1.8 °C | 8.2 °C | 96.01 mm |
| Annual | 6.8 °C | 18.8 °C | 1199.4 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 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 | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |