It could feel like it's 115 degrees later this week

Background for a hot summer or heat wave, orange sky with with bright sun and thermometer

The hottest days of the year so far could hit Chicago and the suburbs Wednesday and Thursday, with temperatures expected to climb into the upper 90s and potentially dangerous heat indexes reaching as high as 115 degrees.

An excessive heat watch is already in place from 11 a.m. Wednesday through 8 p.m. Thursday.

Temperatures should climb into the lower 90s Tuesday, with heat indexes throughout many Western suburbs reaching 100 or more degrees

Forecasts from the National Weather Service’s Romeoville bureau show daytime temperatures possibly reaching 95 to 98 degrees Wednesday, with a heat index that could soar to as much as 115 degrees for much of the area.

Temperatures are anticipated to climb even higher Thursday in the daytime hours. Heat indexes should drop slightly, though remaining dangerously high at 110 degrees.

Those temperatures would top the 93-degree high recorded in late July at O’Hare International Airport, the Chicago area’s highest temperature reading so far this year.

Forecasts show a possibility for thunderstorms Wednesday or Thursday over Lake Michigan, which could disrupt the air mass causing the heat.

By Friday, temperatures are expected to fall into the upper 80s, according to National Weather Service meteorologists.

Outdoor activities should be limited in excessive heat, but anyone who has to be out should take care to remain hydrated and take many breaks in the shade or indoors, experts warn.

From today’s Daily Herald