Washington Court House, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.8 °C (low) to 16.7 °C (high). Annual precipitation averages 1050.3 Millimeters. Washington Court House is located in USDA Plant Hardiness Zone 6b. 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 | -6.2 °C | 2.6 °C | 75.95 mm |
| February | -5.1 °C | 4.4 °C | 65.53 mm |
| March | -0.7 °C | 10.1 °C | 95.76 mm |
| April | 4.9 °C | 17.1 °C | 107.19 mm |
| May | 11.1 °C | 22.7 °C | 115.57 mm |
| June | 16.1 °C | 27.2 °C | 108.71 mm |
| July | 17.6 °C | 28.5 °C | 102.87 mm |
| August | 16.4 °C | 28.1 °C | 84.84 mm |
| September | 12.2 °C | 25.4 °C | 69.09 mm |
| October | 6.1 °C | 18.7 °C | 74.93 mm |
| November | 0.5 °C | 11.1 °C | 74.42 mm |
| December | -3.3 °C | 4.9 °C | 75.44 mm |
| Annual | 5.8 °C | 16.7 °C | 1050.3 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |