Lake Bluff, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.4 °C (low) to 13.9 °C (high). Annual precipitation averages 1007.1 Millimeters. 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 | -8.3 °C | -0.6 °C | 53.85 mm |
| February | -6.8 °C | 1.3 °C | 52.32 mm |
| March | -1.9 °C | 6.6 °C | 57.91 mm |
| April | 3.6 °C | 12.5 °C | 105.41 mm |
| May | 9.1 °C | 18.7 °C | 118.87 mm |
| June | 14.7 °C | 24.3 °C | 108.2 mm |
| July | 18.5 °C | 27.2 °C | 101.6 mm |
| August | 18.3 °C | 26.3 °C | 99.82 mm |
| September | 13.9 °C | 22.8 °C | 102.11 mm |
| October | 7.3 °C | 16.2 °C | 85.6 mm |
| November | 0.9 °C | 8.8 °C | 68.83 mm |
| December | -5 °C | 2.4 °C | 52.58 mm |
| Annual | 5.4 °C | 13.9 °C | 1007.1 mm |
| 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 : -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 |