St. Louis heat warning runs through Friday night, with index near 112

An Extreme Heat Warning is in effect for St. Louis through 10 p.m. Friday, July 3, and the National Weather Service says heat index values could reach 112. That is hot enough to change errands, work breaks, outdoor plans, and how long people can safely stay outside. For St. Louis residents, this is not just a warm spell. It is a day-level safety issue.

What to change today

The City of St. Louis says people should limit outdoor activity during midday, schedule workouts or practices early or later in the day, drink more water than usual, and wear loose, lightweight clothing. The city also warns that people exercising in extreme heat are more likely to become dehydrated and develop heat-related illness. If someone feels faint or weak, city guidance points to getting to a cool environment and stopping activity.

That advice matters for workers, parents, delivery drivers, commuters, athletes, and anyone waiting outside for long stretches. The National Weather Service says heat-related illnesses rise significantly during extreme heat and high humidity. It also says to check on relatives and neighbors, especially people who may not have reliable air conditioning or who have trouble getting around in the heat.

Where to cool off

The city’s cooling-center page lists public and nonprofit locations across St. Louis and says that during periods of extreme heat, the city can declare a heat emergency and open community centers as cooling centers. It also tells residents to call 2-1-1 for the most up-to-date information, including county cooling centers and hours before heading out.

Residents who want alert updates can also use the city’s NotifySTL system, which is designed to send emergency alerts for severe weather, critical incidents, service disruptions, and evacuations. Children, older adults, outdoor workers, and anyone without dependable cooling face the biggest risk, and pets should never be left in vehicles. If heat stroke symptoms appear, that is an emergency. Call 911.

Sources

• National Weather Service St. Louis — Extreme Heat Warning summary
• City of St. Louis Health Department — Extreme heat safety tips