ST. LOUIS, Missouri–Illinois Border – The early morning sky hangs low and gray over the Mississippi River, a sure sign of change ahead. Moist, mild air drifts across the Gateway City this Tuesday, but a round of rain will soon move in, signaling the last unsettled stretch before a beautiful late-October turnaround.
According to the National Weather Service in St. Louis, scattered showers will build through the afternoon, with the steadiest rain expected after sunset. Localized downpours could briefly slow evening commutes along I-70 and I-55. Rain chances peak near 100% late Tuesday, then taper into Wednesday morning as north winds pick up behind the system. Highs will reach near 60°F before cooler, drier air settles in by midweek.
Wednesday stays cloudy and breezy with highs in the mid-50s, but sunshine quickly returns Thursday. Expect a noticeable temperature drop — crisp morning lows near 40°F and clear skies by afternoon. Friday brings the week’s reward: sunshine, light winds, and highs near 61°F — perfect weather for trick-or-treating. Evening temperatures will slip into the low 50s, just cool enough for costumes and jackets.
The weekend starts mild and dry, with only a slight shower chance Saturday. Sunday looks bright and comfortable as early November’s cool pattern gradually sets in.
To be fair, the week begins damp and dull — but ends with the kind of fall weather that defines the Midwest: golden sun, cool air, and a Halloween night tailor-made for outdoor fun.
Five-Day Outlook for St. Louis, MO–IL:
Tue: 60/49 – Rain increasing; breezy evening.
Wed: 55/42 – Cloudy, breezy; cooler.
Thu: 58/41 – Mostly sunny; crisp morning.
Fri: 61/42 – Sunny; ideal Halloween night.
Sat: 56/39 – Mostly cloudy; light shower chance.
