Carrolltown, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 2.6 °C (low) to 13.4 °C (high). Annual precipitation averages 1130 Millimeters. Carrolltown is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.9 °C | -0.2 °C | 84.07 mm |
| February | -8.6 °C | 1.4 °C | 67.56 mm |
| March | -4.8 °C | 6.3 °C | 89.15 mm |
| April | 1.2 °C | 13.6 °C | 94.49 mm |
| May | 7.3 °C | 19.3 °C | 105.16 mm |
| June | 11.9 °C | 23.7 °C | 105.41 mm |
| July | 14.2 °C | 25.8 °C | 113.03 mm |
| August | 13.2 °C | 24.9 °C | 106.93 mm |
| September | 9.4 °C | 21.3 °C | 108.71 mm |
| October | 3.7 °C | 15 °C | 81.28 mm |
| November | -2.1 °C | 8 °C | 85.6 mm |
| December | -5.9 °C | 2.1 °C | 88.65 mm |
| Annual | 2.6 °C | 13.4 °C | 1130.04 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| 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 |