North Chicago, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.2 °C (low) to 13.7 °C (high). Annual precipitation averages 953.5 Millimeters. North Chicago 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 | -8.5 °C | -0.7 °C | 53.85 mm |
| February | -7 °C | 1.2 °C | 51.82 mm |
| March | -2.1 °C | 6.4 °C | 54.61 mm |
| April | 3.4 °C | 12.3 °C | 97.79 mm |
| May | 9.1 °C | 18.4 °C | 112.52 mm |
| June | 14.7 °C | 23.9 °C | 107.44 mm |
| July | 18.2 °C | 26.9 °C | 93.98 mm |
| August | 18.1 °C | 26.2 °C | 95.25 mm |
| September | 13.7 °C | 22.7 °C | 88.14 mm |
| October | 7.1 °C | 16.1 °C | 81.53 mm |
| November | 0.6 °C | 8.7 °C | 64.01 mm |
| December | -5.1 °C | 2.3 °C | 52.58 mm |
| Annual | 5.2 °C | 13.7 °C | 953.52 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 |