Jennerstown, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.4 °C (low) to 14.2 °C (high). Annual precipitation averages 1194.6 Millimeters. Jennerstown 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.5 °C | 0.9 °C | 90.42 mm |
| February | -7.5 °C | 2.3 °C | 74.42 mm |
| March | -3.9 °C | 7.1 °C | 102.62 mm |
| April | 2.5 °C | 14.6 °C | 102.87 mm |
| May | 7.9 °C | 19.9 °C | 120.4 mm |
| June | 12.7 °C | 23.9 °C | 120.14 mm |
| July | 14.9 °C | 26.1 °C | 110.74 mm |
| August | 14 °C | 25.4 °C | 104.9 mm |
| September | 10 °C | 21.9 °C | 100.58 mm |
| October | 4.3 °C | 15.6 °C | 88.14 mm |
| November | -1.1 °C | 9 °C | 87.12 mm |
| December | -4.9 °C | 3.3 °C | 92.2 mm |
| Annual | 3.4 °C | 14.2 °C | 1194.55 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |