St. Louis rolled out of bed Tuesday to patchy river-valley fog and upper-60s temps, with the day set to crank up quickly to a sunny high near 91°F this afternoon. Light northeast breezes and mostly clear skies will help flip the switch from cool to toasty, and the rising humidity will make it feel plenty muggy by late day.
Foggy Mornings, Sunny Afternoons
Low-lying spots and river valleys may deal with reduced visibility during the early commute, so it is worth giving yourself a little extra travel time. The fog should lift by mid-morning, with light northeast winds and plenty of sunshine taking over. Afternoon highs will land around 90–92°F, solidly in shorts-and-water-bottle territory.
Heat Rises Late Week; Spotty Storms Possible
Humidity ticks up later in the week, and heat-index values could push into the 100–105°F range by Thursday and Friday. Scattered, afternoon-driven showers and thunderstorms become more likely on those days, and any storm that pops could bring a brief but heavy downpour. The National Weather Service has more on the building heat and increasing storm chances, so check the full forecast at NWS St. Louis.
Plan Ahead
For morning drives, expect pockets of fog and plan a little cushion in your schedule. For outdoor plans later this week, try to knock out the heavy lifting in the cooler morning hours. If you or someone you look after is sensitive to heat, the city lists cooling centers and related resources on the City of St. Louis site. Keep an eye on the afternoon forecast each day, since a quick-hitting storm could briefly disrupt games, practices, or events with heavy rain or lightning.
