As a second day of sweltering temperatures blanket the area, roughly 48,000 people remain without power in the western suburbs.
As of 7 a.m., about 48,000 ComEd customers remained without power, said Arlana Johnson, spokeswoman with ComEd. She said 39,000 of those customers are located in the utility's northern region, which include the western suburbs, including the areas of Wheaton, Lombard, Addison and Elmhurst.
She said ComEd remains on track to have the majority of residents back on line Wednesday night, but admitted that some isolated areas that recorded the worst damage from Sunday's storms could remain in the dark until Thursday.
"Those are areas where we have to rebuild entire systems from the ground up," she said. "But, ComEd crews will be working around the clock to get everyone back up as soon as possible."
She said 180 crews are coming in from neighboring states to help with the restoration, joining the 440 crews from Illinois that are out in the field right now.
She said ComEd crews will be working through the July 4 holiday until every last customer is online.
The restoration is taking place at a time when temperatures are expected to climb to 98 degrees this afternoon, with a heat index topping out at between 105 and 110, meteorologists from the National Weather Service said.
People living in the areas without power are urged to get to cooling centers or stay with family members until power can be fully restored.
The lack of power prompted DuPage officials to proclaim a countywide state of emergency.
Towns were cleaning up Monday after a powerful storm swept through portions of the suburbs Sunday, knocking down trees and power lines, snarling traffic and damaging property.
Sunday's fierce weather produced winds of 80 to 90 mph, hail and more than an inch of rain in a band that ripped through portions of DuPage and Cook counties.
"It pretty much developed in western Illinois and then blew up as it came toward us," said forecaster Amy Seeley of the National Weather Service in Romeoville. "We just had a very unstable atmosphere."
Jim Keeney, weather program manager for the NWS Central Region based in Kansas City, said more storms may develop as temperatures remain in the upper 90s through the week.
With a prolonged heat wave expected, cooling centers have opened at Yorktown Center in Lombard, Benedictine University in Lisle, the Wheaton Park District Community Center, the Elmhurst Police Department and College of DuPage in Glen Ellyn, among other locations.
David Gervino, emergency management coordinator for DuPage's Office of Homeland Security and Emergency Management, said there were no reports of injury or death.
"We're expecting (power) restoration efforts to take several days," he said.
ComEd said more than 400 crews were working around the clock Monday, with additional groups from Wisconsin, Kansas City and other Midwest locations expected to arrive Tuesday.
Here's a look at how the recovery is shaping up.
Cleanup begins in Roselle
In Roselle, where roughly 2,000 homes and businesses lost power Sunday, officials said village crews began collecting downed tree limbs on Monday and will continue through Friday. Residents are being asked to place damaged tree limbs in their parkways.
Bartlett spared the worst
Bartlett village officials said that compared to other communities in DuPage County, damage is not very bad.
Paul Kuester, director of public works, said there are tree limbs down and some trees snapped throughout town, but he was not aware of any major concerns. The last report from ComEd said there were 245 customers without service.
Kuester said it would be a long clean up, and assistant to the village administrator Steve Bosco said Bartlett is "very fortunate" to have been on the northern edge of the storm and that the damage is "nothing more than we can handle."
Schaumburg removes trees
In Schaumburg, about three or four trees had to be taken down Sunday and another 13 trimmed due to storm damage they sustained, Village Manager Ken Fritz said. But the single biggest disruption was the closure of Plum Grove Road for about two hours due to a power pole that had snapped near the intersection of Schaumburg Road.
Some businesses near Irving Park Road were affected by temporary power outages including Pilot Pete's -- the restaurant at Schaumburg Regional Airport -- and the Daily Herald's printing center.
Hanover Park loses power
Hanover Park officials said the village sustained widespread, but minimal damage compared to its neighbors to the south.
Interim Village Manager Craig Haigh said most of Hanover Park lost power, but it was restored within hours. There also were numerous reports of downed trees and debris, as well as damage to fences, vehicles and roofs.
"We've got a fair amount of damage and it's going to take us some time to get everything cleaned up," Haigh said.
West Chicago in the dark
West Chicago was one of the towns hardest hit. At the height of the storm Sunday, 8,400 of ComEd's 8,650 users in the city were without power. By Monday afternoon, almost half were back in service, Mayor Ruben Pineda said.
It could take between three and four days to completely restore power because tree limbs have to be taken off power lines and new utility poles must be put up in some cases, Pineda said.
At Reed-Keppler Park, crews were working to remove and mulch fallen limbs from 100 trees, many of which are more than 100 years old.
"The north end of this park is like somebody dropped a bomb," Pineda said.
Officials said they hoped to have many streets open Monday night and additional crews were brought in to assist with the removal of downed trees.
The most ravaged area was north of the railroad tracks, Fire Chief Robert Hodge said. "You can see a path where the storm went through town. If you got up in a helicopter I'm sure you'd see where whole trees were taken down, stripped of their leaves, and cut off half-ways," Hodge said.
The fire stations were operating on backup generators, but city hall was closed du e to the power outage.
No fireworks in Wheaton
In Wheaton, where Mayor Michael Gresk declared a state of emergency, the park district on Monday canceled all holiday-related activities, including the July 3 fireworks and July 4 parade.
Officials said the DuPage fairgrounds, where the fireworks were planned, sustained "extensive damage," and the parade route along Main Street remained closed.
Carol Stream power restored
At the height of the storm in Carol Stream, about half the ComEd customers were without power. By noon Monday, that number was down to 21 percent, according to Chris Oakley, assistant to the village manager.
Residents at Colony Park Apartments, a senior living facility at 550 Thornhill Drive, lost power during the storm and many were escorted to the Simkus Recreation Center, which serves as a cooling center. Their power was restored by Sunday night, Oakley said.
Lombard a disaster zone
In Lombard, officials declared a disaster zone after roughly 200 properties sustained damage.
Public Works Director Carl Goldsmith said the area north of St. Charles Road between I-355 and Westmore Meyers Road appeared most affected. At least five structures sustained roof damage from tree limbs and traffic lights were out on areas of North Avenue, Main Street, Grace Street and Roosevelt Road.
Goldsmith said the storm knocked over some tents at Madison Meadow Park, where the annual Taste of Lombard is scheduled to open Tuesday, but the festival was expected to go on as planned.
Village crews asked for mutual aid backup from Des Plaines, McHenry County and other areas. Lombard fire crews also were doing door-to-door well-being checks for seniors, communications coordinator Joelyn Kott said.
Airport sustains roof damage
Crews at DuPage Airport in West Chicago were working to assess and repair roof damage to at least four hangars. But Mark Doles, director of operations planning, said no one was injured and no aircraft were damaged.
Doles said strong winds tore away or lifted up pieces of metal roofing on several of the airport's 30 buildings.
Hospitals lose some power
Central DuPage Hospital in Winfield saw its power interrupted Sunday, causing most of the hospital to go on generators. By 12:30 p.m. Monday, power had been restored to the entire hospital, said CDH spokesman Chris King.
There was no service interruption to patients, he said. At Adventist GlenOaks Hospital in Glendale Heights, power was lost at the height of the storm about 1 p.m., but the hospital's generator kicked in and business went on as normal until power was fully restored by 4 p.m., said Lisa Parro, a hospital spokeswoman.
• Daily Herald staff writers Justin Kmitch, Eric Peterson, Jessica Cilella and Kimberly Pohl contributed to this report.