Steger, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.1 °C (low) to 15.3 °C (high). Annual precipitation averages 1029.5 Millimeters. Steger 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 | -8.6 °C | -0.2 °C | 59.18 mm |
| February | -7 °C | 2.1 °C | 55.63 mm |
| March | -1.8 °C | 8.2 °C | 60.45 mm |
| April | 4 °C | 15.3 °C | 98.3 mm |
| May | 10 °C | 21.3 °C | 113.28 mm |
| June | 15.4 °C | 26.7 °C | 120.14 mm |
| July | 18 °C | 28.9 °C | 113.03 mm |
| August | 17.1 °C | 27.9 °C | 106.43 mm |
| September | 12.8 °C | 24.4 °C | 84.07 mm |
| October | 6.1 °C | 17.2 °C | 89.92 mm |
| November | 0.2 °C | 9.5 °C | 70.87 mm |
| December | -5.4 °C | 2.7 °C | 58.17 mm |
| Annual | 5.1 °C | 15.3 °C | 1029.47 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 |