Washington Boro, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.7 °C (low) to 17.5 °C (high). Annual precipitation averages 1148.3 Millimeters. Washington Boro 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 | -4.9 °C | 4.1 °C | 80.77 mm |
| February | -4.3 °C | 5.5 °C | 65.79 mm |
| March | -0.2 °C | 10.6 °C | 96.27 mm |
| April | 5.2 °C | 17.6 °C | 88.65 mm |
| May | 11 °C | 22.8 °C | 97.79 mm |
| June | 16.3 °C | 27.7 °C | 109.47 mm |
| July | 18.9 °C | 30.1 °C | 108.71 mm |
| August | 17.9 °C | 29.2 °C | 99.57 mm |
| September | 13.9 °C | 25.3 °C | 121.41 mm |
| October | 7.5 °C | 18.7 °C | 109.47 mm |
| November | 1.8 °C | 12.4 °C | 78.99 mm |
| December | -2.3 °C | 6.5 °C | 91.44 mm |
| Annual | 6.7 °C | 17.5 °C | 1148.33 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 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |