Helen, West Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 5.5 °C (low) to 17.9 °C (high). Annual precipitation averages 1241.6 Millimeters. Helen 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.1 °C | 5.6 °C | 99.06 mm |
| February | -3.8 °C | 7.7 °C | 90.93 mm |
| March | -0.6 °C | 12.4 °C | 108.46 mm |
| April | 4.4 °C | 19.1 °C | 114.05 mm |
| May | 9.7 °C | 23.2 °C | 132.08 mm |
| June | 14.3 °C | 26.8 °C | 115.57 mm |
| July | 16.6 °C | 28.4 °C | 135.64 mm |
| August | 15.9 °C | 27.8 °C | 102.11 mm |
| September | 12.3 °C | 25 °C | 86.11 mm |
| October | 5.6 °C | 19.1 °C | 76.45 mm |
| November | -0.1 °C | 12.8 °C | 79.76 mm |
| December | -2.9 °C | 7.3 °C | 101.35 mm |
| Annual | 5.5 °C | 17.9 °C | 1241.57 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |