Arnold City, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.4 °C (low) to 16.9 °C (high). Annual precipitation averages 1069.3 Millimeters. Arnold City 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.8 °C | 3.3 °C | 78.99 mm |
| February | -5.3 °C | 4.8 °C | 69.09 mm |
| March | -1.4 °C | 10.1 °C | 87.12 mm |
| April | 3.9 °C | 17.4 °C | 87.63 mm |
| May | 9.7 °C | 22.6 °C | 106.43 mm |
| June | 14.6 °C | 26.8 °C | 113.28 mm |
| July | 16.9 °C | 28.9 °C | 107.95 mm |
| August | 16.3 °C | 28.5 °C | 93.47 mm |
| September | 12.3 °C | 25.1 °C | 88.9 mm |
| October | 6 °C | 18.3 °C | 76.96 mm |
| November | 0.7 °C | 11.6 °C | 78.99 mm |
| December | -3 °C | 5.7 °C | 80.52 mm |
| Annual | 5.4 °C | 16.9 °C | 1069.33 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 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |