Excessive Heat Warning

Chicago heat wave: Records reached, relief in sight?

An excessive heat warning for all of Northeastern Illinois continues through 8 p.m. Thursday

Editor's Note: You can find Wednesday's updates here. Our updates for Thursday continue below.

As a heat wave continues to grip the entire Chicago area, some schools are continuing to cancel activities and classes for a second day.

According to the National Weather Service, an excessive heat warning, with heat index values as high as 117 degrees will continue for all of northeastern Illinois until 8 p.m. Thursday.

"Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun and check up on relatives and neighbors," an alert from the NWS said. "Young children and pets should never be left unattended in vehicles under any circumstances."

As the heat and humidity builds, we're keeping track of updates for Thursday here.

Severe thunderstorm watch in Kenosha County in Wisconsin, Lake and McHenry counties in Illinois canceled

The National Weather Service has issued a severe thunderstorm watch for Kenosha County in Wisconsin and Lake and McHenry counties in Illinois.

The watch was scheduled to be in effect until 10 p.m., though it was canceled shortly before 9 p.m. Thursday evening.

Residents in Tinley Park, Orland Park asked to conserve electricity by ComEd

ComEd is asking residents in Tinley Park and Orland Park to conserve electricity this afternoon due to an equipment issue.

According to the company, ComEd is “addressing a localized and emergent issue,” and as a result, they have had to take a piece of equipment in the area out of service.

Residents in Tinley Park and Orland Park are being asked to conserve energy until at least 7:30 p.m. Thursday to “reduce the risk of outages” in the area.

Customers are being asked to conserve power in the following ways:

-Turn off or unplug all unnecessary lights and devices at this time

-Raise their thermostats by at least 2-to-3 degrees

-Do not use appliances like dishwashers, washing machines and dryers

Chicago ties heat index record, high temperature mark

The city of Chicago has officially tied a record for warmest heat index in recorded history, and also has hit 100 degrees for the first time in more than a decade.

As of 2:51 p.m. at O’Hare International Airport, the air temperature had reached 100 degrees, according to the National Weather Service.

That temperature not only ties a record for Aug. 24 that has stood since 1947, but also marks the first 100-degree day in Chicago since July 2012, according to officials.

That combination made for a heat index of a staggering 118 degrees, tying July 13, 1995 as the warmest heat index ever recorded at the airport.

Where temperatures stand Thursday afternoon

Here's a look at where temperatures and heat index levels stand as of 1 p.m. Thursday, according to the National Weather Service.

As the mercury rises, what does Chicago's winter projection look like?

Last winter provided a surprising amount of rain and warmer-than-normal temperatures in the Chicago area, but could the region be in for a repeat?

According to the National Weather Service’s Climate Prediction Center, that very well could be the case.

As of their latest update earlier this month, forecasters believe there is a greater than 95% chance that an El Niño weather pattern will persist through Feb. 2024.

In fact, there is a 66% chance that this year’s El Niño could be considered a “strong” event, pushing temperatures more than 1.5 degrees Celsius above their normal levels.

As a result, forecasts for the coming winter in the Chicago area are suggesting that residents could experience warmer-than-normal temperatures, with below-normal precipitation.

Here's the full story.

'One of the hotter games I've ever played'

After the White Sox showed up the Seattle Mariners 5-4 in Wednesday's sweltering temperatures, White Sox outfielder Andrew Benintendi wasn't shy about how much he was feeling the heat.

"I've never sweat that much on the bench before," Benintendi said. "It was one of the hotter games I've ever played, and I've played some hot ones before in Kansas City."

Illinois, Wisconsin power outage watch

Thousands of customers Wednesday were without power in Wisconsin and Illinois amid the heat wave, officials reported.

According to WE Energy in Wisconsin, upwards of 4,000 customers were without power in areas around Kenosha County at times Wednesday. By Thursday however, those numbers had fallen to fewer than 100.

According to ComEd, approximately 340 customers in Illinois were without power as of Thursday morning. Wednesday, more than 2,000 customers were without power.

You can check outages near you here.

Chicago-area schools cancel activities, and classes in some cases

Schools across Chicago and the suburbs are making adjustments to their schedules for a second day in a row.

Here are the latest changes we know of:

  • Buffalo Grove High School (District 214) will be closed Thursday "because of mechanical problems related to the HVAC system."
  • Chicago Public Schools will cancel all outdoor athletic games Thursday, and will move all practices indoors
  • Plainfield School District 202 says it will keep students inside for recess, physical education, athletics and other activities Thursday
  • Mount Carmel High School will shift to half-day schedules beginning Wednesday, with school dismissing at 12:10 p.m. for the remainder of the week. Sports practices will be moved to morning hours.
  • Valley View’s Lukancic Middle School has canceled baseball and softball games, as well as cross-country meets through Thursday because of the heat.
  • Oak Park River Forest High School will hold PE classes indoors Thursday. Classes held in rooms without air conditioning will be temporarily moved. All athletic practices will be moved to hours before school begins.
  • Crystal Lake District 47 - Canterbury and West Elementary will be closed until Friday
  • Cook County School District 130 will be closed Thursday as an "emergency day" in response to the weather conditions
  • Cicero District 99 - Abe Lincoln Elementary will shift to e-learning due to non-functioning air conditioning systems
  • District #302 Kaneland Schools in Maple Park are closed

According to CPS officials, all classrooms have air conditioning, and crews will work to fix any cooling problems that arise this week.

YMCA Chicago offering complimentary guest passes to beat the heat

All 14 YMCA of Metro Chicago locations will offer complimentary guest passes Thursday, a YMCA spokesperson said.

"Folks can take advantage of the facilities and air-conditioned spaces, including: gyms & basketball courts, pools (where applicable), fitness areas, computer labs, exercise classes, and more," the spokesperson added.

More information can be found here.

How high did the heat index get?

According to NWS data, a temperature of 98 degrees was measured at O’Hare International Airport, which would make it the hottest Aug. 23 on record in the city of Chicago.

The previous record of 97 degrees had stood since 1947, according to officials.

O’Hare also measured a heat index of 116 degrees, the second-warmest heat index ever recorded at the airport.

In other parts of the area though, things felt even hotter. In Morris, located in Grundy County, temperatures hit only 95 degrees, but the heat index measured at 124 degrees, according to officials.

Dixon’s airport also registered a staggering heat index of 121 degrees, while Joliet’s airport measured a heat index of 119.

Here's a full list of Wednesday's heat index levels across the area.

Metra implements speed restrictions

Riding the Metra this week? Your train may run a bit slower.

Officials with Metra say that the agency is ordering a reduction in speed on all trains because of the extreme heat currently gripping the Chicago area.

Those restrictions, which will be in effect Wednesday afternoon, will likely lead to delays throughout the Metra system, with officials asking riders to allow extra time to complete their journeys.

According to Metra officials, when temperatures exceed 95 degrees, trains must reduce speeds by at least 10 mph to compensate for heat-related stress on the tracks.

Here's the full story.

Symptoms of heat stroke vs. heat exhaustion

Dangerously-hot temperatures are about to arrive in the Chicago area, and experts are urging the public to acquaint themselves with the symptoms of heat-related illness.

"The biggest problem is, once again, the way that our body usually dissipates heat to keep our temperature where it should be is through sweating and then evaporation of that sweat off the bod," Lewis said, adding that with high temperatures and high humidity, "what happens is, it's very hard for our body to evaporate that heat or that perspiration."

"So we really can't cool ourselves. And that's where we get into trouble during these weather conditions," he said.

Symptoms of heat stroke can include confusion, loss of consciousness, hot, dry skin, seizures, or high body temperature. Heat exhaustion symptoms can include muscle cramps, headaches, dizziness and more.

Additional cooling centers in Chicago, Cook county

The city of Chicago has announced it will open additional cooling centers, and will extend cooling center hours, amid dangerously-high heat indices in the area.

A full list of the available information can be found here.

MORE: Chicago Fire Department to escalate responses, activate ambulances ahead of hot weather

Cooling centers are also available in numerous suburban communities, including across Cook County at courthouses Skokie, Maywood, Markham, Rolling Meadows Leighton, Bridgeview and the Daley Center Courthouse.

Visit your county's website to see if there is a cooling center near you.

The best advice for staying safe during Chicago's heat wave

While advice from experts during periods of extreme heat may seem obvious, such heat "often results in the highest annual number of deaths among all weather-related disasters," a spokesperson for Cook County Health said.

So what exactly should residents keep in mind over the next few days as the mercury continues to rise? As NBC Chicago combed through dozens of lists and bits of advice from the Red Cross, the National Weather Service, the city of Chicago and more, these five tips were among the most cited.

What to do if you have car trouble

Round-the-clock “hot weather patrols” will be launched by the Illinois Tollway this week.

According to officials, those patrols will search for drivers stranded in disabled vehicles, and will respond to *999 motorist assistance calls.

Tollway officials urge motorists to save *999 in their phones in the event of an emergency, and to remain in their vehicles should they need assistance.

Emergency kits with water and jumper cables are also encouraged.

What is the “heat index?”

To put things as simply as possible, a “heat index” is a reading that indicates how the air temperature feels, rather than the official temperature reading.

There are a few limitations to heat indices, including its measurement of shaded, lightly-windy areas instead of sunny areas.

Here's a full explanation.

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