Urban

Of 70 native species examined for the Chicago Wilderness region, suitable habitat for 15 of them was projected to decline under both climate scenarios. One species projected to decline in habitat suitability, black cherry, is one of the most common species in the Chicago region according to the Regional Tree Census. Other common species projected to decline are white oak, eastern white pine, quaking aspen, and paper birch.

Chicago and areas right around Lake Michigan in Indiana are in hardiness zone 6a (mean annual lowest temperature -10 to -5 °F; -21 to -23 °C), and most of the surrounding area is currently in hardiness zone 5b (mean annual lowest temperature -15 to -10 ° F; -26 to -23 °C). By the end of the century, hardiness zones are expected to shift to between 6a and 6b under a low emissions scenario up to potentially 7b under a high emissions scenario. However, it is important to keep in mind that hardiness zones are based on a 30-year average and some very cold winters could still be possible.

Over the past century (1916 to 2007), the frequency of extreme and exceptional droughts in Illinois and Indiana decreased. Exceptional droughts are the most severe form of drought experienced in the region, and extreme droughts are the second most severe. Until the recent drought of 2012, all of the exceptional droughts were prior to 1970, and the majority of them occurred during the dust bowl era of the 1930s. In general, more recent drought events have been less intense in their severity, duration, and spatial extent compared to earlier in the 20th Century.