Caln, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.6 °C (low) to 17.4 °C (high). Annual precipitation averages 1287.3 Millimeters. Caln 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.9 °C | 4.2 °C | 93.98 mm |
| February | -5.6 °C | 5.4 °C | 76.45 mm |
| March | -1.4 °C | 10.2 °C | 109.98 mm |
| April | 4.4 °C | 17.2 °C | 99.06 mm |
| May | 9.9 °C | 22.6 °C | 101.85 mm |
| June | 14.9 °C | 27.3 °C | 121.41 mm |
| July | 17.9 °C | 29.7 °C | 124.46 mm |
| August | 16.9 °C | 29.1 °C | 114.3 mm |
| September | 12.7 °C | 25.4 °C | 128.27 mm |
| October | 6.1 °C | 18.8 °C | 118.87 mm |
| November | 0.7 °C | 12.3 °C | 88.14 mm |
| December | -3 °C | 6.6 °C | 110.49 mm |
| Annual | 5.6 °C | 17.4 °C | 1287.26 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |