As September rolls in, St. Louis and much of Missouri are preparing for a shift in the weather as a cold front approaches late Wednesday. The front is expected to bring a wave of cooler, drier air, signaling the end of a warm, humid start to the month. The next several days will see a mix of scattered showers, thunderstorms, and cooler temperatures, offering an early preview of fall weather.
Wednesday: A Stormy End to the Day
By late Wednesday afternoon, residents of St. Louis can expect the weather to turn more unsettled. A cold front sweeping across Missouri will bring a strong chance of rain and thunderstorms. The National Weather Service in St. Louis warns that these storms may develop as early as the afternoon in central and southeast Missouri, but the heaviest rain is likely to hit during the evening commute in the St. Louis metro area.
As the front moves eastward, widespread rain will be possible throughout the region. Heavier downpours could lead to slick roads and reduced visibility, so drivers are advised to allow extra travel time, especially during the evening hours.
Thursday: A Cool Down
Once the cold front passes through, temperatures will significantly drop. Thursday will see cooler, more comfortable weather with highs only reaching the upper 60s. The cooler air will be accompanied by clearing skies, offering a refreshing break from the humid conditions that have defined the early part of the month.
The overnight temperatures could dip into the low 50s, with some rural areas possibly experiencing temperatures in the upper 40s. This cool, crisp air will be a stark contrast to the summer-like conditions earlier in the week.
Labor Day Weekend: Partly Cloudy and Pleasant
Labor Day weekend will offer residents a mix of pleasant weather and a slight chance of rain. On Monday, the skies will be partly cloudy, and temperatures will be mild, ranging from the low 70s to the low 80s. There’s a small chance of rain, especially in central and southeast Missouri, but for the most part, Labor Day will be dry and pleasant.
Tuesday will bring mostly sunny skies, with just an isolated shower possible in southeast Missouri. Highs will range from 76 to 82 degrees, with lows in the mid-50s.
The Week Ahead: Fall-Like Weather
By midweek, as the cooler air settles in, St. Louis will experience a noticeable drop in temperatures. Thursday will bring highs only in the 68 to 76-degree range, with clear skies in the afternoon. Overnight lows will be in the 40s and 50s, which could be a chilly change for those used to the warmer summer nights.
Friday will offer more partly cloudy skies, with temperatures ranging from 75 to 83 degrees, and lows in the 50s and 60s. The cooler weather will make for a pleasant end to the workweek, but residents are advised to keep an eye on the skies through Wednesday and Thursday as the potential for rain and storms remains high.
Five-Day Forecast for St. Louis, Missouri
- Labor Day (Monday): Partly cloudy with a slight chance of rain in central and southeast Missouri. High 71–84 / Low 54–62
- Tuesday: Mostly sunny with an isolated shower in southeast Missouri. High 76–82 / Low 54–62
- Wednesday: Becoming partly to mostly cloudy, with a chance of showers and thunderstorms. High 78–86 / Low 45–55
- Thursday: Clearing and cooler. High 68–76 / Low 48–54
- Friday: Partly cloudy. High 75–83 / Low 50–56
Missouri residents, particularly those in St. Louis, should be prepared for a significant change in the weather as the week progresses. With the potential for rain and thunderstorms late Wednesday, followed by cooler, fall-like temperatures by Thursday, the weather will offer a refreshing shift from the humid start to September. It’s a good time to keep an umbrella on hand and dress in layers as the temperatures fluctuate.
