Allison, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.1 °C (low) to 16.9 °C (high). Annual precipitation averages 1096.3 Millimeters. Allison 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 | -6.2 °C | 3.3 °C | 81.28 mm |
| February | -5.6 °C | 4.8 °C | 71.12 mm |
| March | -1.7 °C | 10.2 °C | 90.17 mm |
| April | 3.7 °C | 17.5 °C | 90.68 mm |
| May | 9.4 °C | 22.6 °C | 109.73 mm |
| June | 14.3 °C | 26.8 °C | 114.05 mm |
| July | 16.7 °C | 28.8 °C | 113.54 mm |
| August | 15.9 °C | 28.4 °C | 95.5 mm |
| September | 11.9 °C | 24.9 °C | 88.9 mm |
| October | 5.6 °C | 18.3 °C | 77.22 mm |
| November | 0.3 °C | 11.4 °C | 80.77 mm |
| December | -3.4 °C | 5.6 °C | 83.31 mm |
| Annual | 5.1 °C | 16.9 °C | 1096.27 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 |