Big Run, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.5 °C (low) to 15.2 °C (high). Annual precipitation averages 1119.6 Millimeters. Big Run is located in USDA Plant Hardiness Zone 6a. 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 | -7.8 °C | 1.2 °C | 81.79 mm |
| February | -7.3 °C | 2.9 °C | 62.23 mm |
| March | -3.6 °C | 7.9 °C | 83.31 mm |
| April | 2 °C | 15.7 °C | 93.73 mm |
| May | 7.7 °C | 21.5 °C | 98.04 mm |
| June | 12.7 °C | 25.4 °C | 112.78 mm |
| July | 14.9 °C | 27.5 °C | 120.9 mm |
| August | 14.1 °C | 27 °C | 101.85 mm |
| September | 10.4 °C | 23.3 °C | 102.87 mm |
| October | 4.2 °C | 16.7 °C | 85.85 mm |
| November | -0.8 °C | 9.6 °C | 86.36 mm |
| December | -4.6 °C | 3.6 °C | 89.92 mm |
| Annual | 3.5 °C | 15.2 °C | 1119.63 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |