St. Louis is starting Thursday under clear skies and upper-60s temps, but the quiet will not last. A Flood Watch kicks in at 1 p.m. CDT Thursday, June 25, 2026, and runs through 7 a.m. CDT Friday, June 26, 2026, with multiple rounds of thunderstorms expected this afternoon and overnight. Forecasters say heavy, training downpours could trigger flash flooding in low-lying and urban spots.
The National Weather Service office in St. Louis says the watch covers the city and much of the surrounding region, with the highest flood threat ramping up from late afternoon into the overnight period, according to NWS St. Louis. A few storms could also punch out damaging wind gusts, and a corridor of rich moisture this evening may let storms repeatedly track over the same neighborhoods.
What To Expect
Most of the morning should stay mainly dry with only a slight chance of showers. Storm chances climb through the day and into tonight, with forecast probabilities jumping from around 30 to 40 percent this afternoon to about 70 to 90 percent overnight. The big issues will be short bursts of very heavy rain, localized flash flooding of streets and creeks, and occasional gusty winds. Drivers should be ready for slow, water-covered roads and the potential for closures at low bridges and underpasses during the most intense storms.
Flood Safety
Do not drive through flooded roadways. Turn Around, Do not Drown if you come up on standing water. If you live in a flood-prone area, move vehicles and valuables to higher ground, secure outdoor furniture, and follow local emergency instructions if warnings are issued.
Looking Ahead
The wet pattern is expected to ease on Friday, but a strong warm-up follows. Highs are forecast to rise into the mid 90s beginning Sunday, June 28, 2026, then push into the upper 90s early next week. If you need a place to cool off, the City of St. Louis keeps a list of cooling centers and public air-conditioned spaces. Check locations and hours at the City of St. Louis.
This story will be updated if the Flood Watch is upgraded to warnings or if significant flooding is reported. Before heading out this evening, check radar and official products from the National Weather Service.
