Chicago Heights, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.4 °F (low) to 59.6 °F (high). Annual precipitation averages 40.3 Inches. Chicago Heights 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 | 17.0 °F | 31.9 °F | 2.27 in. |
| February | 19.7 °F | 35.8 °F | 2.15 in. |
| March | 29.0 °F | 46.8 °F | 2.39 in. |
| April | 39.2 °F | 59.3 °F | 3.91 in. |
| May | 50.1 °F | 70.0 °F | 4.46 in. |
| June | 60.1 °F | 79.9 °F | 4.71 in. |
| July | 64.7 °F | 83.9 °F | 4.43 in. |
| August | 63.0 °F | 82.0 °F | 4.15 in. |
| September | 55.4 °F | 75.9 °F | 3.27 in. |
| October | 43.3 °F | 63.1 °F | 3.51 in. |
| November | 32.6 °F | 49.1 °F | 2.78 in. |
| December | 22.6 °F | 37.0 °F | 2.3 in. |
| Annual | 41.4 °F | 59.6 °F | 40.33 in. |
| 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 : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |