Wellersburg, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.7 °C (low) to 16.3 °C (high). Annual precipitation averages 1071.6 Millimeters. Wellersburg 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 | -6.1 °C | 2.7 °C | 74.42 mm |
| February | -5.6 °C | 4.6 °C | 69.09 mm |
| March | -1.9 °C | 9.4 °C | 94.23 mm |
| April | 3.6 °C | 17.1 °C | 95 mm |
| May | 8.9 °C | 22.1 °C | 117.6 mm |
| June | 13.6 °C | 26.3 °C | 110.24 mm |
| July | 15.9 °C | 28.6 °C | 91.44 mm |
| August | 14.9 °C | 27.8 °C | 87.12 mm |
| September | 11.2 °C | 24.1 °C | 96.27 mm |
| October | 5.3 °C | 17.6 °C | 79.5 mm |
| November | 0.1 °C | 10.7 °C | 74.17 mm |
| December | -3.7 °C | 4.9 °C | 82.55 mm |
| Annual | 4.7 °C | 16.3 °C | 1071.63 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 | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |