But on Tuesday night, as temperatures dropped and storms rolled in, some people on the water were caught off guard.
The Evanston Fire Department says eight boats were overturned along Lighthouse Beach. No injuries were reported, but the fire department, the United States Coast Guard and others worked together to rescue two adults in the water.
Charlie Ruklick from Evanston watched as the storms rolled in.
"I didn't expect it to be so non rain-like and then all of a sudden a downpour," said Ruklick.
Before the rain, sweltering heat was top of mind. Those along the lakefront found relief in the shade and water. With more dangerous heat to come on Wednesday, doctors warn of the signs of heat exhaustion.
"People will start to feel perhaps dizzy, lightheaded, nauseous," said Dr. Trevor Lewis, Chair of Emergency Medicine at Cook County Health.
Dr. Lewis also warned of the symptoms of heat stroke, which can include confusion, nausea, dizziness, and potential loss of consciousness.
If you must be out in the heat, Dr. Lewis recommends wearing loose-fitting, light-colored clothing and hydrating with water rather than caffeine.
"Most importantly, check on other people," said Dr. Lewis. "The elderly, your kids, your pets, you know you got to make sure that everybody's safe, not just yourself."
Remember, during extreme heat you can request a well-being check for your loved one by calling 3-1-1.