Mannington, West Virginia has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 40.5 °F (low) to 63.7 °F (high). Annual precipitation averages 48.9 Inches. Mannington is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.6 °F | 39.4 °F | 3.7 in. |
| February | 22.2 °F | 42.7 °F | 3.18 in. |
| March | 28.7 °F | 52.1 °F | 4.0 in. |
| April | 38.4 °F | 65.8 °F | 3.94 in. |
| May | 48.2 °F | 74.0 °F | 4.96 in. |
| June | 57.0 °F | 81.2 °F | 4.81 in. |
| July | 61.2 °F | 84.5 °F | 5.76 in. |
| August | 59.8 °F | 83.4 °F | 4.24 in. |
| September | 52.6 °F | 77.9 °F | 3.72 in. |
| October | 40.6 °F | 66.3 °F | 3.46 in. |
| November | 31.5 °F | 53.9 °F | 3.19 in. |
| December | 25.3 °F | 43.3 °F | 3.89 in. |
| Annual | 40.5 °F | 63.7 °F | 48.85 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |