Mill Run, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.3 °C (low) to 15.2 °C (high). Annual precipitation averages 1062.5 Millimeters. Mill Run is located in USDA Plant Hardiness Zone 6b. 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 | -7.2 °C | 1.4 °C | 72.64 mm |
| February | -6.6 °C | 3.1 °C | 60.96 mm |
| March | -2.8 °C | 7.9 °C | 83.57 mm |
| April | 3.1 °C | 15.6 °C | 86.11 mm |
| May | 8.7 °C | 21 °C | 106.93 mm |
| June | 13.7 °C | 25.4 °C | 99.82 mm |
| July | 15.9 °C | 27.7 °C | 94.49 mm |
| August | 15.1 °C | 26.9 °C | 90.17 mm |
| September | 11.3 °C | 23.1 °C | 105.92 mm |
| October | 5.2 °C | 16.6 °C | 93.22 mm |
| November | -0.2 °C | 9.7 °C | 87.12 mm |
| December | -4.2 °C | 3.7 °C | 81.53 mm |
| Annual | 4.3 °C | 15.2 °C | 1062.48 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 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |