Owaneco, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.2 °C (low) to 17.6 °C (high). Annual precipitation averages 1029 Millimeters. Owaneco is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7 °C | 2 °C | 57.4 mm |
| February | -5.2 °C | 4.8 °C | 52.32 mm |
| March | -0.1 °C | 11.1 °C | 71.88 mm |
| April | 5.7 °C | 18.3 °C | 111 mm |
| May | 11.9 °C | 23.9 °C | 119.38 mm |
| June | 16.8 °C | 28.6 °C | 120.4 mm |
| July | 18.5 °C | 30.3 °C | 97.54 mm |
| August | 17.4 °C | 29.5 °C | 84.33 mm |
| September | 12.8 °C | 26.8 °C | 83.06 mm |
| October | 6.5 °C | 19.8 °C | 85.85 mm |
| November | 0.7 °C | 11.3 °C | 84.07 mm |
| December | -4 °C | 4.7 °C | 61.72 mm |
| Annual | 6.2 °C | 17.6 °C | 1028.95 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |