Keensburg, 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 19.2 °C (high). Annual precipitation averages 1194.6 Millimeters. Keensburg 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.7 °C | 4.4 °C | 89.92 mm |
| February | -3.1 °C | 7.3 °C | 72.9 mm |
| March | 1.4 °C | 12.8 °C | 104.9 mm |
| April | 7.2 °C | 19.7 °C | 128.02 mm |
| May | 13.2 °C | 25 °C | 131.06 mm |
| June | 18 °C | 29.7 °C | 116.84 mm |
| July | 19.6 °C | 31.3 °C | 108.2 mm |
| August | 18.4 °C | 30.8 °C | 80.77 mm |
| September | 14.1 °C | 27.7 °C | 86.11 mm |
| October | 7.7 °C | 21.2 °C | 87.12 mm |
| November | 1.9 °C | 13.1 °C | 98.81 mm |
| December | -2.6 °C | 6.8 °C | 89.92 mm |
| Annual | 7.6 °C | 19.2 °C | 1194.57 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 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 |