Henning, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.4 °C (low) to 16.5 °C (high). Annual precipitation averages 1028.5 Millimeters. Henning is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.9 °C | 0.7 °C | 61.98 mm |
| February | -6.3 °C | 3.3 °C | 54.1 mm |
| March | -1.1 °C | 9.7 °C | 70.36 mm |
| April | 4.7 °C | 17.2 °C | 102.87 mm |
| May | 11.2 °C | 23.2 °C | 117.86 mm |
| June | 16.3 °C | 27.8 °C | 119.13 mm |
| July | 17.8 °C | 29.2 °C | 109.47 mm |
| August | 16.6 °C | 28.4 °C | 84.33 mm |
| September | 12.3 °C | 25.8 °C | 82.04 mm |
| October | 6.1 °C | 18.9 °C | 84.33 mm |
| November | 0.3 °C | 10.4 °C | 81.79 mm |
| December | -4.8 °C | 3.6 °C | 60.2 mm |
| Annual | 5.4 °C | 16.5 °C | 1028.46 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |