Homer Glen, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.1 °F (low) to 60.3 °F (high). Annual precipitation averages 40.2 Inches. Homer Glen 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 | 16.4 °F | 32.1 °F | 2.19 in. |
| February | 19.0 °F | 35.9 °F | 2.06 in. |
| March | 28.6 °F | 47.6 °F | 2.47 in. |
| April | 39.3 °F | 60.5 °F | 3.95 in. |
| May | 50.0 °F | 71.4 °F | 4.84 in. |
| June | 60.0 °F | 81.0 °F | 4.54 in. |
| July | 64.6 °F | 85.0 °F | 4.42 in. |
| August | 63.0 °F | 83.0 °F | 4.19 in. |
| September | 55.4 °F | 77.1 °F | 3.34 in. |
| October | 42.9 °F | 63.7 °F | 3.51 in. |
| November | 32.3 °F | 49.4 °F | 2.49 in. |
| December | 22.0 °F | 37.0 °F | 2.21 in. |
| Annual | 41.1 °F | 60.3 °F | 40.21 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 |