St. Louis, Mo. – Drivers and residents across eastern Missouri will face another round of summer-like heat and poor air quality Tuesday, September 16, as the St. Louis metro climbs into the mid-90s with humidity pushing heat index values even higher. Travelers along Interstate 70 and surrounding highways should prepare for both traffic slowdowns and breathing difficulties due to ozone concerns.
According to the National Weather Service in St. Louis, an Air Quality Alert remains in effect through 8 p.m. Monday, with maximum ozone levels expected to pose health risks. The St. Louis Clean Air Partnership urges residents to limit driving, avoid idling cars, and reduce outdoor activity, especially for children, seniors, and those with asthma or respiratory illness.
Temperatures in St. Louis will hit 94 degrees Tuesday, staying hot and dry through midweek before thunderstorm chances increase Thursday afternoon and Friday. Forecasters warn even a brief storm could create dangerous lightning and localized flooding during commutes. Cooling relief is unlikely, with highs holding in the 80s and 90s into the weekend.
Residents should stay hydrated, check on vulnerable neighbors, and avoid outdoor work during peak afternoon heat. Officials caution that more weather advisories may be issued later this week as storm chances rise.
Five-Day Forecast for St. Louis, Missouri
- Tuesday: Sunny, high near 94. Low 68.
- Wednesday: Sunny, high near 93. Low 67.
- Thursday: 30% chance of storms after 1 p.m. High 92. Low 68.
- Friday: 30% chance of storms. High 87. Low 65.
- Saturday: 20% chance of storms. High 84. Low 64.
