Chalfont, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.3 °C (low) to 17.6 °C (high). Annual precipitation averages 1217.4 Millimeters. Chalfont 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 | -5.3 °C | 4.2 °C | 84.58 mm |
| February | -4.6 °C | 5.7 °C | 71.37 mm |
| March | -0.6 °C | 10.4 °C | 101.85 mm |
| April | 5 °C | 17.3 °C | 96.01 mm |
| May | 10.4 °C | 22.7 °C | 106.43 mm |
| June | 15.7 °C | 27.7 °C | 111.51 mm |
| July | 18.4 °C | 30.3 °C | 120.4 mm |
| August | 17.5 °C | 29.3 °C | 111.76 mm |
| September | 13.5 °C | 25.6 °C | 111.51 mm |
| October | 6.9 °C | 18.8 °C | 107.95 mm |
| November | 1.5 °C | 12.6 °C | 83.57 mm |
| December | -2.4 °C | 6.9 °C | 110.49 mm |
| Annual | 6.3 °C | 17.6 °C | 1217.43 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 | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |