Lake Bluff, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.6 °F (low) to 57 °F (high). Annual precipitation averages 39.7 Inches. Lake Bluff is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 17.0 °F | 30.9 °F | 2.12 in. |
| February | 19.8 °F | 34.3 °F | 2.06 in. |
| March | 28.6 °F | 43.8 °F | 2.28 in. |
| April | 38.5 °F | 54.5 °F | 4.15 in. |
| May | 48.3 °F | 65.6 °F | 4.68 in. |
| June | 58.5 °F | 75.7 °F | 4.26 in. |
| July | 65.3 °F | 80.9 °F | 4.0 in. |
| August | 64.9 °F | 79.4 °F | 3.93 in. |
| September | 57.1 °F | 73.1 °F | 4.02 in. |
| October | 45.1 °F | 61.2 °F | 3.37 in. |
| November | 33.6 °F | 47.8 °F | 2.71 in. |
| December | 23.0 °F | 36.3 °F | 2.07 in. |
| Annual | 41.6 °F | 57 °F | 39.65 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 |