Chapman, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.6 °C (low) to 16.1 °C (high). Annual precipitation averages 1328.9 Millimeters. Chapman 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 | -7.2 °C | 2.6 °C | 95.5 mm |
| February | -6.5 °C | 4.2 °C | 75.95 mm |
| March | -2.4 °C | 8.7 °C | 99.82 mm |
| April | 3.3 °C | 16.1 °C | 105.66 mm |
| May | 9 °C | 21.7 °C | 107.95 mm |
| June | 14.1 °C | 26.1 °C | 129.03 mm |
| July | 16.7 °C | 28.7 °C | 130.56 mm |
| August | 15.7 °C | 27.7 °C | 124.97 mm |
| September | 11.7 °C | 24 °C | 135.38 mm |
| October | 5.3 °C | 17.4 °C | 121.16 mm |
| November | -0.2 °C | 10.9 °C | 90.93 mm |
| December | -4.1 °C | 4.9 °C | 112.01 mm |
| Annual | 4.6 °C | 16.1 °C | 1328.92 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |