St. Louis, Missouri — A late-season cool down will settle into Missouri early Friday, May 8, bringing below-normal temperatures and the potential for patchy overnight frost that could impact travel and early-season vegetation across St. Louis, Kansas City, Columbia, Springfield, and Jefferson City.
According to NOAA’s Climate Prediction Center, temperatures will run 20–30% below normal through May 14, with the coolest stretch arriving Friday night into early Saturday. The most likely window for frost development is between 3 a.m. and 7 a.m. Saturday, mainly across northern and central Missouri.
That cooler air will create localized impacts. Patchy frost is possible in sheltered and low-lying areas near Columbia and Jefferson City, where temperatures may dip into the mid-30s. Sensitive plants could see minor damage, and early morning drivers may encounter slick spots on elevated surfaces such as bridges along I-70 and I-44.
Light rain moving through Friday night may leave roads damp, and cooler temperatures before sunrise could allow moisture to settle on road surfaces. Low-lying roads and flood-prone underpasses in St. Louis, along with drainage-prone areas near the Missouri River in Kansas City, could see minor water pooling that reduces visibility and slows travel within minutes of heavier showers.
Drivers should remain alert for changing conditions early Saturday, particularly on bridges and in rural valleys where temperatures drop fastest. Residents should consider covering sensitive vegetation overnight.
The highest risk for patchy frost and early morning travel impacts centers on Saturday between 3 a.m. and 7 a.m.
