Coolville, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.5 °C (low) to 18.1 °C (high). Annual precipitation averages 1111.8 Millimeters. Coolville 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 | -5.8 °C | 4.2 °C | 84.33 mm |
| February | -4.9 °C | 6.3 °C | 73.41 mm |
| March | -1.1 °C | 11.6 °C | 98.3 mm |
| April | 4.5 °C | 19.3 °C | 97.28 mm |
| May | 10.2 °C | 23.8 °C | 110.24 mm |
| June | 15.1 °C | 28 °C | 116.59 mm |
| July | 17.2 °C | 29.7 °C | 118.87 mm |
| August | 16.4 °C | 29.4 °C | 86.61 mm |
| September | 12.3 °C | 25.6 °C | 89.92 mm |
| October | 5.5 °C | 19.7 °C | 74.42 mm |
| November | 0.2 °C | 12.8 °C | 75.44 mm |
| December | -3.1 °C | 6.8 °C | 86.36 mm |
| Annual | 5.5 °C | 18.1 °C | 1111.77 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 |