Belle Vernon, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.5 °C (low) to 17.2 °C (high). Annual precipitation averages 1061 Millimeters. Belle Vernon 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 | -5.7 °C | 3.7 °C | 78.49 mm |
| February | -5.2 °C | 5.1 °C | 68.83 mm |
| March | -1.3 °C | 10.3 °C | 87.38 mm |
| April | 4.1 °C | 17.7 °C | 86.87 mm |
| May | 9.8 °C | 22.8 °C | 105.66 mm |
| June | 14.8 °C | 27.1 °C | 112.52 mm |
| July | 17.1 °C | 29.2 °C | 105.92 mm |
| August | 16.4 °C | 28.7 °C | 92.71 mm |
| September | 12.4 °C | 25.3 °C | 87.63 mm |
| October | 6.1 °C | 18.6 °C | 75.95 mm |
| November | 0.8 °C | 11.8 °C | 78.74 mm |
| December | -2.8 °C | 6.1 °C | 80.26 mm |
| Annual | 5.5 °C | 17.2 °C | 1060.96 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 |