St. Louis is waking up to a murky, patchy fog bank Wednesday, March 4, 2026, with showers likely at times and a high near 62°F. Visibility will be reduced in spots through the morning, and scattered to numerous thunderstorms are expected to fire up through midday and the afternoon. Commuters should be ready for slower travel during the late-morning into afternoon drive when the strongest storms move in.
Timing And Impacts
Showers and thunderstorms are on the table before 7 a.m., with patchy fog expected to lift into the late morning. A more organized cluster of storms is then forecast to roll through between about noon and 5 p.m. According to the National Weather Service St. Louis, the most numerous storms will be centered over southeastern Missouri and southwestern Illinois and could bring damaging wind gusts, small hail and an isolated tornado. Forecasters also highlight a corridor where 2–4 inches of rain may fall, which could trigger brief urban or poor-drainage flooding. With a high near 62°F and light east winds, the mix of wet roads and periods of low visibility could make the afternoon commute a slog.
Tonight And The Week Ahead
Showers and thunderstorms are expected to linger into the evening and tonight, with a low around 54°F and a steady chance of rain. A warm and drier break is on tap for Thursday, before temperatures jump Friday into the upper 70s with gusty south winds and another round of storms possible Friday night into Saturday morning. For background on local impacts and resources, including a storm-spotter talk scheduled March 5 at the William J. Harrison Center (3140 Cass Ave), see fog, thunder and traffic headaches.
How To Prepare
Build in extra travel time this morning and again later in the day, slow down in fog and leave more space between vehicles when roads are wet. Avoid standing water and never drive through flooded streets, since flash flooding can develop quickly where storms repeatedly track over the same area. Keep your phone charged, have an indoor backup ready for outdoor plans, and stay tuned to local alerts if you live in a low-lying or poor-drainage neighborhood. If you plan to be outside Friday, secure loose outdoor items ahead of the gusty south winds expected later in the week.
