Fallston, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.2 °C (low) to 16.2 °C (high). Annual precipitation averages 1014 Millimeters. Fallston 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.3 °C | 2.3 °C | 77.72 mm |
| February | -5.8 °C | 3.9 °C | 57.4 mm |
| March | -1.7 °C | 9.1 °C | 77.72 mm |
| April | 3.8 °C | 16.6 °C | 93.98 mm |
| May | 9.6 °C | 22.1 °C | 95.5 mm |
| June | 14.5 °C | 26.4 °C | 107.19 mm |
| July | 16.7 °C | 28.6 °C | 99.31 mm |
| August | 15.9 °C | 27.9 °C | 87.38 mm |
| September | 12.2 °C | 24.3 °C | 88.65 mm |
| October | 6.2 °C | 17.6 °C | 77.47 mm |
| November | 0.8 °C | 10.7 °C | 73.66 mm |
| December | -3.3 °C | 4.8 °C | 77.98 mm |
| Annual | 5.2 °C | 16.2 °C | 1013.96 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 100-125 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 |