St. Louis, Missouri – Drivers and residents across eastern Missouri and western Illinois face a return to stormy, dangerously hot weather through early next week, with heat index values soaring past 100°F and occasional thunderstorm threats each afternoon. Thursday opens with a slight chance of storms, but the big story remains the relentless summer heat and rising humidity.
According to the National Weather Service in St. Louis, a 20 percent chance of scattered thunderstorms lingers Thursday, mainly after 2 p.m., with similar slight risks expected Thursday night. Highs will reach the mid-90s through Sunday, but oppressive humidity will push the heat index as high as 101°F. South winds may offer little relief, and spotter activation is not expected at this time.
Residents in St. Louis, St. Charles, and Jefferson County, along with Madison and Monroe in Illinois, should monitor for brief downpours or lightning, especially during the late afternoon and evening hours. Conditions look drier Friday and Saturday, but another round of pop-up showers and storms could return Sunday evening into early next week, keeping travel and outdoor plans at risk. Anyone working or exercising outdoors should hydrate frequently and limit strenuous activity to early morning or evening.
This pattern of extreme heat and occasional storms holds through at least Wednesday. Stay tuned for updates as advisories could be issued if the thunderstorm threat increases or if heat warnings become necessary.
Five Day Forecast for St. Louis, MO:
- Thursday: Mostly sunny, slight chance of thunderstorms, high 94°F.
- Friday: Sunny and hot, high 96°F.
- Saturday: Mostly sunny, high 96°F.
- Sunday: Mostly sunny, high 95°F; 20% chance of showers after 1 p.m.
- Monday: Partly cloudy, slight chance of storms, high 92°F.
