Bonnie, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.6 °C (low) to 18.8 °C (high). Annual precipitation averages 1162.3 Millimeters. Bonnie is located in USDA Plant Hardiness Zone 6b. 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 | -4.8 °C | 4.3 °C | 80.26 mm |
| February | -3.2 °C | 7 °C | 69.85 mm |
| March | 1.6 °C | 12.7 °C | 99.82 mm |
| April | 7.3 °C | 19.2 °C | 127 mm |
| May | 13.2 °C | 24.3 °C | 134.11 mm |
| June | 17.9 °C | 29.3 °C | 120.4 mm |
| July | 19.8 °C | 30.9 °C | 106.17 mm |
| August | 18.6 °C | 30.5 °C | 78.74 mm |
| September | 14.1 °C | 27.1 °C | 79.76 mm |
| October | 7.6 °C | 20.7 °C | 83.82 mm |
| November | 2 °C | 12.8 °C | 103.63 mm |
| December | -2.4 °C | 6.6 °C | 78.74 mm |
| Annual | 7.6 °C | 18.8 °C | 1162.3 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 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |