St. Louis, MO – A major pattern shift arrives for the St. Louis region late Wednesday night into Thursday as a cold front brings widespread rainfall, isolated thunderstorms, and a sharp drop in temperatures heading into the end of the week.
According to the National Weather Service St. Louis, rain chances rise quickly after midnight Wednesday. By Thursday morning, much of the region—from St. Louis to Columbia, Farmington, Effingham, and Litchfield—shows 80–98% rain probabilities, marking what forecasters say will be the first meaningful rainfall since the Monday before Thanksgiving.
Thursday’s system may also produce isolated thunderstorms across southeast Missouri and southern Illinois. The rain is expected to shift east by midday, but winds will strengthen behind the front. Gusty northwest winds Thursday afternoon could create difficult travel for high-profile vehicles and may usher in a much cooler air mass.
Highs Thursday will reach the low to mid-50s, but temperatures slide quickly Thursday night as colder air filters in. Overnight lows fall into the 40s, setting the stage for a noticeably cooler Friday.
Friday turns mostly sunny but sharply colder, with highs only in the upper 30s to mid-40s and morning wind chills dipping even lower. Overnight lows Friday night are expected to drop into the 20–25° range, ending the mild stretch that has dominated much of December.
Forecasters encourage residents to prepare for wet roads Thursday morning, breezy afternoon conditions, and the first taste of winterlike temperatures by Friday morning.
