Orland Hills, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.2 °F (low) to 60.4 °F (high). Annual precipitation averages 40.2 Inches. Orland Hills 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.6 °F | 32.3 °F | 2.2 in. |
| February | 19.3 °F | 36.1 °F | 2.08 in. |
| March | 28.7 °F | 47.6 °F | 2.43 in. |
| April | 39.3 °F | 60.3 °F | 3.95 in. |
| May | 50.0 °F | 71.2 °F | 4.75 in. |
| June | 60.0 °F | 81.0 °F | 4.49 in. |
| July | 64.6 °F | 85.2 °F | 4.46 in. |
| August | 63.0 °F | 83.2 °F | 4.19 in. |
| September | 55.5 °F | 77.0 °F | 3.32 in. |
| October | 43.1 °F | 63.7 °F | 3.49 in. |
| November | 32.4 °F | 49.5 °F | 2.56 in. |
| December | 22.1 °F | 37.2 °F | 2.25 in. |
| Annual | 41.2 °F | 60.4 °F | 40.17 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |