More than 2,000 customers in Homewood-Flossmoor, 1,000 in Tinley Park and hundreds in Orland Park are impacted.
Restoration is estimated at noon, July 4.
ComEd on Tuesday said it expects a "multi-day restoration effort" to bring power back to all customers. The company attributed damage to power lines and widespread outages to sustained winds with gusts in excess of 75 mph, as well as tree damage, toppled wires and downed power lines.
According to ComEd, 758 crews were deployed Tuesday to handle restoration efforts.
"Our crews are working around the clock to restore power to our customers as quickly and safely as possible and will continue to do so until all our customers are restored," ComEd said in a press release.