The Chicago area will once again see plenty of sunshine and warm temperatures on Sunday, but a few small changes are in the offing for the forecast in the coming days.
Sunday will start with warm conditions, driven by a thick layer of warm air that remains planted firmly in place over the Midwest. That dense air has led to an accumulation of pollutants in the atmosphere, boosting them to hazardous levels.
As a result, an air quality warning is in effect for numerous counties in northeast Illinois, including McHenry, Lake, Kane, DuPage, Cook, Kendall, Grundy and Will counties, as well as Lake, Porter and LaPorte counties in northwest Indiana.
Residents with respiratory conditions, such as asthma, are advised to stay indoors or to limit time outdoors, and residents are also urged to avoid activities like mowing lawns that can put more pollutants into the atmosphere.
In addition to the lowered air quality, residents will also noticed a slight increase in humidity levels Sunday. Dew points are beginning to creep upward into the mid-60s, and that trend will continue into Monday, leading to some changes in the forecast for the work week.
High temperatures on Sunday are expected to top out in the upper-80s to low-90s, with some widely scattered showers possible late Sunday, especially south of Interstate 80, according to the National Weather Service.
Monday will bring more of the same in terms of heat, with temps once again in the upper-80s to low-90s, but the humidity will also continue to creep upward, causing more of a chance of scattered showers and thunderstorms, especially in the evening hours.
That chance of rain will only increase throughout the week, with temperatures beginning to very slowly drop on Tuesday. Highs will still be in the mid-to-upper 80s through at least Thursday, but likely won’t drop too much further as warm air continues to dominate the forecast.