Missouri and western Illinois start calm, with crisp air and bright skies, but conditions begin shifting by late day as clouds build over the region.
According to the National Weather Service, St. Louis, Chesterfield, St. Charles, and Belleville will climb from the upper 40s this morning to near 64°F this afternoon before isolated showers develop after 10 p.m. While most daylight hours stay dry, a few early evening sprinkles cannot be ruled out, especially north of I-44.
This is part of a broader system bringing scattered showers across the Midwest while colder-than-normal air lingers through the weekend.
Rain remains light, but impacts are immediate where it falls. Slick pavement could develop quickly on I-44, I-55, and I-64, especially near low-lying ramps and river-adjacent roadways where water tends to collect. Reduced visibility may affect late commuters and overnight drivers.
Drivers should slow down on wet roads and watch for pooling water near underpasses and poorly drained intersections. Keep headlights on in any rain and allow extra stopping distance.
Temperatures dip to around 45°F tonight, setting up a cool but quieter stretch. Saturday and Sunday trend drier and warmer, with highs rising from the low 60s Saturday to the mid-70s Sunday.
By early next week, a stronger push of warm air lifts highs into the low 80s Monday, followed by increasing chances for showers and thunderstorms Monday afternoon through Tuesday. Some storms could bring gusty winds and brief heavy rain.
Expect the most noticeable travel impacts after 10 p.m. tonight as roads turn slick and visibility drops in scattered showers.
