Schaefferstown, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.9 °C (low) to 16.9 °C (high). Annual precipitation averages 1214.9 Millimeters. Schaefferstown is located in USDA Plant Hardiness Zone 7a. 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 | -5.8 °C | 3.3 °C | 84.84 mm |
| February | -5.3 °C | 4.9 °C | 67.56 mm |
| March | -1.2 °C | 9.8 °C | 103.12 mm |
| April | 4.7 °C | 17.1 °C | 99.57 mm |
| May | 10.2 °C | 22.4 °C | 98.04 mm |
| June | 15.4 °C | 26.9 °C | 120.65 mm |
| July | 17.8 °C | 29.6 °C | 115.06 mm |
| August | 16.9 °C | 28.6 °C | 106.93 mm |
| September | 13.1 °C | 24.7 °C | 122.17 mm |
| October | 6.9 °C | 18.3 °C | 111.25 mm |
| November | 1.1 °C | 11.9 °C | 84.84 mm |
| December | -3.1 °C | 5.8 °C | 100.84 mm |
| Annual | 5.9 °C | 16.9 °C | 1214.87 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |