Terra Alta, West Virginia has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 39.3 °F (low) to 58.3 °F (high). Annual precipitation averages 55.7 Inches. Terra Alta is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.9 °F | 34.6 °F | 4.53 in. |
| February | 20.8 °F | 38.0 °F | 4.12 in. |
| March | 27.2 °F | 46.3 °F | 4.7 in. |
| April | 37.4 °F | 59.9 °F | 4.77 in. |
| May | 47.3 °F | 68.2 °F | 5.46 in. |
| June | 55.5 °F | 75.2 °F | 5.41 in. |
| July | 59.2 °F | 78.5 °F | 5.87 in. |
| August | 58.0 °F | 77.6 °F | 4.72 in. |
| September | 51.4 °F | 72.4 °F | 4.07 in. |
| October | 40.5 °F | 61.2 °F | 3.76 in. |
| November | 31.0 °F | 49.0 °F | 3.74 in. |
| December | 23.8 °F | 39.0 °F | 4.54 in. |
| Annual | 39.3 °F | 58.3 °F | 55.69 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| 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 |