Glencoe, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.2 °F (low) to 58.4 °F (high). Annual precipitation averages 38.5 Inches. Glencoe 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 | 18.7 °F | 31.8 °F | 2.08 in. |
| February | 21.5 °F | 35.4 °F | 1.99 in. |
| March | 30.0 °F | 45.0 °F | 2.19 in. |
| April | 39.9 °F | 56.5 °F | 3.78 in. |
| May | 50.2 °F | 68.1 °F | 4.65 in. |
| June | 60.3 °F | 78.0 °F | 4.26 in. |
| July | 66.9 °F | 82.7 °F | 3.68 in. |
| August | 66.4 °F | 81.2 °F | 4.09 in. |
| September | 58.9 °F | 74.5 °F | 3.38 in. |
| October | 46.5 °F | 62.7 °F | 3.5 in. |
| November | 34.8 °F | 48.3 °F | 2.63 in. |
| December | 24.7 °F | 37.0 °F | 2.27 in. |
| Annual | 43.2 °F | 58.4 °F | 38.5 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |