Tinley Park, 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 15.6 °C (high). Annual precipitation averages 1018.5 Millimeters. Tinley Park 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 | -8.5 °C | 0.1 °C | 56.13 mm |
| February | -7 °C | 2.2 °C | 52.83 mm |
| March | -1.8 °C | 8.5 °C | 61.21 mm |
| April | 3.9 °C | 15.5 °C | 99.82 mm |
| May | 9.9 °C | 21.6 °C | 118.11 mm |
| June | 15.6 °C | 27.1 °C | 115.06 mm |
| July | 18.1 °C | 29.3 °C | 113.28 mm |
| August | 17.2 °C | 28.2 °C | 106.17 mm |
| September | 12.9 °C | 24.8 °C | 83.31 mm |
| October | 6.2 °C | 17.4 °C | 88.14 mm |
| November | 0.2 °C | 9.7 °C | 66.8 mm |
| December | -5.3 °C | 2.8 °C | 57.66 mm |
| Annual | 5.1 °C | 15.6 °C | 1018.52 mm |
| 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 : -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 |