Bryn Athyn, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.6 °C (low) to 17.8 °C (high). Annual precipitation averages 1236.2 Millimeters. Bryn Athyn is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.1 °C | 4.7 °C | 89.92 mm |
| February | -3.3 °C | 6.3 °C | 67.31 mm |
| March | 0.6 °C | 10.7 °C | 108.46 mm |
| April | 6.1 °C | 17.3 °C | 95.76 mm |
| May | 11.6 °C | 22.7 °C | 105.41 mm |
| June | 16.8 °C | 27.7 °C | 112.78 mm |
| July | 19.9 °C | 30.2 °C | 121.92 mm |
| August | 18.9 °C | 29.3 °C | 130.3 mm |
| September | 14.9 °C | 25.7 °C | 110.24 mm |
| October | 8.4 °C | 19.1 °C | 100.33 mm |
| November | 2.8 °C | 12.9 °C | 83.82 mm |
| December | -1.2 °C | 7.3 °C | 109.98 mm |
| Annual | 7.6 °C | 17.8 °C | 1236.23 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |