A heat wave expected to bring a stretch of hot temperatures the Chicago area hasn't seen in years began Thursday, bringing with it the potential for storms.
Scorching temperatures are expected soar into the 90s and remain through Sunday, feeling even hotter thanks to high humidity.
An Excessive Heat Warning took effect for nearly all of the Chicago area Thursday afternoon. With maximum heat index values between 105 and 115 degrees, the warning will last until Friday evening for many counties.
For Ogle, Lee, LaSalle, Grundy, Kankakee, Livingston, Iroquois and Ford counties, however, an Excessive Heat Watch will continue until Saturday afternoon.
The National Weather Service’s heat index is a measure of how hot it really feels when relative humidity is factored in with the actual air temperature.
A Severe Thunderstorm Watch was also issued for virtually every county in the metropolitan area Thursday evening. The watch remains in effect until midnight.
A Severe Thunderstorm Warning was also issued for Cook, DeKalb, DuPage, Kane, Lake, Boone, and McHenry counties until 8:45 p.m.
Storms started popping up in parts of the area early Thursday afternoon. A Severe Thunderstorm Warning was issued for Lake County in northwest Indiana until 1:45 p.m. and another in Porter County until 2:15 p.m. Later, another warning took effect in Benton and Jasper counties until 4:30 p.m.
The storms have the potential to bring with them wind gusts at about 60 mph and nickel-sized hail. Wind gusts of 62 mph and 50 mph were reported in storms in Gary and Hammond, respectively.
Because of the high temperatures, Metra is warning its riders that they may experience 10 to 15 minute delays. Trains need to go a bit slower because of possible heat-related stress on the tracks.
The heat wave impacting Chicago will stretch across many cities in the central U.S., bringing the hottest weather of the year so far and triple-digit temperatures. It will mark the first time the city has seen a stretch of temperatures this high since 2013. In that year, July 16-19 saw highs in the 90s. A similar four-day stretch hasn't been seen since in the Chicago area.
Sweltering conditions remain through Friday, for another windy, brutally hot and extra humid day. Temperatures hover in the mid 90s with heat index values in the dangerous category once again, between 105 to 115 degrees.
The National Weather Service warns heat-related illnesses such as heat strokes, heat cramps and heat exhaustion are possible in the extremely hot and humid weather.
More people die each year from heat than lightning, tornadoes, hurricanes and floods, according to weather officials.
Residents are urged to reduce strenuous activity, drink plenty of water and other non-alcohol fluids and avoid getting to much sun.
The temperatures fall for the weekend, but only slightly. Saturday will be hazy, hot and humid with the chance of thunderstorms developing late in the day. Highs could reach into the mid-90s.
On Sunday the Chicago area will see a small relief from the heat. A partly sunny and less humid day is in store with highs in the mid-80s to low-90s, and cooler along the lakefront.