Mason, West Virginia has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.2 °C (low) to 18.8 °C (high). Annual precipitation averages 1100.1 Millimeters. Mason is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.2 °C | 4.9 °C | 81.79 mm |
| February | -4.1 °C | 7.1 °C | 74.93 mm |
| March | -0.6 °C | 12.4 °C | 99.06 mm |
| April | 5.1 °C | 19.9 °C | 92.96 mm |
| May | 10.9 °C | 24.5 °C | 111.51 mm |
| June | 15.7 °C | 28.6 °C | 109.47 mm |
| July | 17.8 °C | 30.3 °C | 116.33 mm |
| August | 17 °C | 29.8 °C | 88.65 mm |
| September | 12.9 °C | 26.6 °C | 88.65 mm |
| October | 6.1 °C | 20.3 °C | 77.72 mm |
| November | 0.7 °C | 13.4 °C | 73.15 mm |
| December | -2.5 °C | 7.4 °C | 85.85 mm |
| Annual | 6.2 °C | 18.8 °C | 1100.07 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |