By VOTP News STL Staff
September 15, 2026
ST. LOUIS — A heat advisory is in effect for St. Louis city from 11 a.m. to 7 p.m. Tuesday as another blast of late-season heat pushes the afternoon high near 100 degrees.
Conditions were mostly clear and near 73 degrees before sunrise. Periods of sunshine are expected through much of the day, with a thunderstorm possible late in the afternoon. The overnight low is forecast near 74.
The combination of high temperatures and humidity can raise the risk of dehydration and heat-related illness. Residents spending time outside should drink water regularly, limit strenuous activity during the hottest part of the day and check on older adults, young children and people without dependable air conditioning.
Any thunderstorm could briefly change travel conditions. Drivers should watch for sudden heavy rain, reduced visibility and gusty winds. Forecast details can change during the day, so check current alerts before heading out.
Tuesday at a glance
- Heat advisory: 11 a.m. to 7 p.m. for St. Louis city
- Morning: Mostly clear and warm
- Afternoon: High near 100 degrees; late thunderstorm possible
- Overnight low: About 74 degrees
Source:
National Weather Service St. Louis Forecast Office
Featured image: VOTP News STL weather illustration. AI-generated; not a live weather photograph.
