Ohio, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.6 °C (low) to 14.7 °C (high). Annual precipitation averages 963.7 Millimeters. Ohio is located in USDA Plant Hardiness Zone 5b. 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 | -10.7 °C | -1.6 °C | 44.7 mm |
| February | -8.6 °C | 0.9 °C | 44.2 mm |
| March | -3.1 °C | 7.8 °C | 59.94 mm |
| April | 2.9 °C | 15.3 °C | 91.19 mm |
| May | 9.4 °C | 21.6 °C | 121.92 mm |
| June | 14.9 °C | 26.4 °C | 126.24 mm |
| July | 16.8 °C | 28.1 °C | 102.11 mm |
| August | 15.6 °C | 27.1 °C | 100.58 mm |
| September | 10.9 °C | 24 °C | 87.63 mm |
| October | 4.5 °C | 17 °C | 75.44 mm |
| November | -1.7 °C | 8.6 °C | 60.71 mm |
| December | -7.3 °C | 1.4 °C | 49.02 mm |
| Annual | 3.6 °C | 14.7 °C | 963.68 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |