Osage, West Virginia has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.5 °C (low) to 17.4 °C (high). Annual precipitation averages 1151.1 Millimeters. Osage 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 | -5.8 °C | 3.9 °C | 87.88 mm |
| February | -4.9 °C | 5.7 °C | 80.26 mm |
| March | -1.3 °C | 10.9 °C | 96.77 mm |
| April | 4.1 °C | 18.3 °C | 99.06 mm |
| May | 9.8 °C | 23.2 °C | 112.78 mm |
| June | 14.7 °C | 27.2 °C | 109.47 mm |
| July | 17.1 °C | 29.2 °C | 122.68 mm |
| August | 16.3 °C | 28.7 °C | 99.06 mm |
| September | 12.3 °C | 25.4 °C | 88.14 mm |
| October | 5.9 °C | 18.7 °C | 81.03 mm |
| November | 0.6 °C | 11.8 °C | 81.03 mm |
| December | -3.1 °C | 6 °C | 92.96 mm |
| Annual | 5.5 °C | 17.4 °C | 1151.12 mm |
| 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 : -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 |