St. Louis, MO–IL – The Mississippi River was shrouded in low clouds early Saturday morning, giving the St. Louis metro area a gray, quiet start to the weekend. However, forecasters say the calm weather won’t last long. A slow-moving system is expected to bring widespread showers across eastern Missouri and southwestern Illinois by late Sunday, leading to a wet and cooler start to the week.
The Weather System: Cloudy Skies and Light Winds Dominate Saturday
According to the National Weather Service (NWS) in St. Louis, skies will remain mostly cloudy throughout Saturday with highs near 62°F and light east winds. Although much of the day will stay dry, isolated sprinkles could appear by evening, especially across Franklin County, MO, and St. Clair County, IL.
Forecasters say this pattern signals the arrival of a moisture-rich system from the south that will begin spreading clouds and light rain across the region through the weekend. The weather agency noted that overnight temperatures will hover near 52°F, maintaining the chilly and damp feel into Sunday morning.
Sunday into Monday: Increasing Rain and Cooler Conditions
The gray skies will deepen on Sunday, with rain chances rising steadily throughout the day. By afternoon, light rain is expected to become more widespread, particularly along the I-70 corridor and through the Metro East region.
“Scattered showers will develop Sunday afternoon and continue into early Monday,” the National Weather Service said in its latest briefing.
Rain is likely to persist through Monday morning, tapering off gradually by the afternoon. Temperatures will remain steady in the low 60s, but the combination of cloud cover and steady east winds will make it feel noticeably cooler. Motorists are advised to expect wet roads during the Monday morning commute, and residents with outdoor plans should keep umbrellas handy through early Tuesday.
No Severe Threat but a Noticeable Pattern Change
While no severe weather is expected from this system, meteorologists say it marks a transition toward a wetter and cooler trend that could persist through Halloween week.
“This weekend’s system won’t bring storms, but it’s the first sign of a more unsettled weather pattern moving in,” meteorologists explained.
The shift comes as seasonal jet stream patterns begin steering Pacific moisture across the Midwest, increasing rain frequency while pulling in cooler Canadian air. The result: a stretch of cloudy, damp days typical of late October.
Midweek Outlook: Clearing Skies and a Cool Down
By Wednesday, the region should see partial sunshine returning, though temperatures will dip further, with highs near 58°F and lows around 42°F. A brief break in the wet weather is expected midweek before another system could bring rain chances back by late Thursday or Friday.
Meteorologists say this pattern aligns with the broader fall transition, as cold fronts begin to dominate the region’s weather heading into November.
Five-Day Forecast for St. Louis, MO–IL
- Saturday: 62°F / 52°F – Cloudy; light east breeze.
- Sunday: 62°F / 51°F – Increasing rain chances late.
- Monday: 61°F / 52°F – Showers likely; damp and breezy.
- Tuesday: 60°F / 46°F – Cloudy; lingering light rain possible.
- Wednesday: 58°F / 42°F – Partly sunny; cooler midweek trend.
Conclusion
While this weekend brings no severe threat, residents across the St. Louis metro and southern Illinois should prepare for gray skies, light rain, and cooler temperatures through early next week. The unsettled weather marks the start of a chilly November pattern, with occasional sunshine midweek before rain chances return toward the end of the month.
What are your plans for the wet weekend ahead? Share your thoughts in the comments below.
