Cicero, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.3 °C (low) to 15.2 °C (high). Annual precipitation averages 1010.2 Millimeters. Cicero 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.4 °C | -0.1 °C | 55.37 mm |
| February | -5.9 °C | 2 °C | 52.58 mm |
| March | -0.9 °C | 7.8 °C | 59.69 mm |
| April | 4.7 °C | 14.8 °C | 100.84 mm |
| May | 10.8 °C | 20.9 °C | 118.87 mm |
| June | 16.5 °C | 26.5 °C | 110.49 mm |
| July | 19.6 °C | 29 °C | 112.78 mm |
| August | 18.9 °C | 27.9 °C | 104.39 mm |
| September | 14.8 °C | 24.4 °C | 82.8 mm |
| October | 7.8 °C | 17.3 °C | 87.88 mm |
| November | 1.4 °C | 9.4 °C | 65.28 mm |
| December | -4.3 °C | 2.9 °C | 59.18 mm |
| Annual | 6.3 °C | 15.2 °C | 1010.15 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 |