Gray skies and a brisk breeze greet early commuters around St. Louis this morning, but the pattern is already shifting. After days of steady clouds and cool air, the Missouri–Illinois border region is poised for a brief December warm-up — only for temperatures to drop sharply again by the weekend.
According to the National Weather Service in St. Louis, skies will begin clearing through the day as southwest winds increase, sending highs climbing into the low 50s. The warmth continues into Wednesday, when gusts up to 25 mph push readings near 46°F before a cold front slides through late in the evening.
By Thursday, a colder air mass takes control, keeping highs near 40°F and lows dropping below freezing. The weekend looks brisk and dry, with highs in the low 40s Friday, dipping into the 20s and even teens by Saturday night — a true December cold snap returning to the Midwest.
Drivers on I-70, I-55, and Route 64 should anticipate crosswinds midweek and slick bridges late week, especially as morning frost becomes more widespread. For now, no major precipitation is expected, but long-range models hint that a rain–snow mix could develop early next week as another cold surge arrives from the Plains.
Five-Day Outlook (St. Louis, MO–IL Region)
- Tuesday: Mostly cloudy, high 53°F, low 48°F.
- Wednesday: Breezy, high 46°F, low 28°F.
- Thursday: Mostly cloudy, high 40°F, low 31°F.
- Friday: Partly sunny, high 42°F, low 20°F.
- Saturday: Mostly sunny, high 37°F, low 11°F.
