ALTON/EDWARDSVILLE/BELLEVILLE — Local and Illinois officials have urged residents in Madison County, St. Clair County and across the state to take precautions as heat indices are expected to top 100 degrees from June 28 through July 3, with many people likely to spend time outdoors ahead of July 4, 2026, celebrations.
Heat indices across the region are predicted to top 100 degrees and soar to nearly 110 degrees in many area locations this week.
The National Weather Service in St. Louis forecasts temperatures in the upper 80s to mid-90s, with heat indices above 100 degrees for several consecutive days for the region. State officials said the prolonged heat increases health and safety risks, particularly for vulnerable populations and people spending extended time outdoors.
Click here for a list of cooling centers in our community.
One concern tied to the warning is that many people will be outside celebrating the July 4 holiday on Friday, July 3, and July 4, and even beforehand.
The Alton Police Department issued a statement Sunday, June 28, 2026, about the upcoming heat warning.
“With the excessive heat, please hydrate and be mindful of exposure. Check on your friends and neighbors,” the department said.
The St. Clair County Emergency Management Agency also issued an alert Sunday urging residents to take the extreme heat warning seriously.
“Stay safe in the heat,” the agency said. “This extreme heat warning goes from Sunday to Friday, July 3, 2026. Heat-related illnesses increase significantly during this type of heat and humidity warning.”
Illinois Gov. JB Pritzker said residents who cannot stay cool at home should seek out public cooling options.
“An extreme heat wave is bringing the hottest temperatures in two years to Illinois, and I encourage Illinoisans to stay safe and hydrated,” Pritzker said. “If you can’t keep cool at home, visit keepcool.illinois.gov to find a cooling center near you.”
“Illinois is facing several days of dangerous heat, and we urge everyone to take these conditions seriously,” said Theodore “Ted” Berger, director of the Illinois Emergency Management Agency and Office of Homeland Security. “Preparedness is key. Limit time outdoors during peak heat, check in on neighbors and those who may need extra assistance, and know where your local cooling centers are. Taking simple steps now can prevent heat-related emergencies and help keep our communities safe throughout this extended heat wave.”
State and local officials advised residents to drink plenty of water, avoid alcohol, wear lightweight and light-colored clothing, take frequent breaks in shaded or air-conditioned places, and limit outdoor activity during the hottest parts of the day. They also said sunscreen with SPF 30 or higher should be applied every two hours.
“As temperatures across Illinois continue to climb, it’s important to take steps to protect yourself and your loved ones from the heat,” said Dr. Sameer Vohra, director of the Illinois Department of Public Health.
“In warm weather, never leave anyone, including pets, inside a closed, parked vehicle. Additionally, apply sunscreen thirty minutes before outdoor activities, drink plenty of water, and call 911 immediately if you or a loved one experiences symptoms of heat stroke like confusion or hallucinations.”
