St. Louis is waking up socked in on Thursday, February 19, 2026, as dense fog tangles the morning commute with visibility down to about a quarter mile in low-lying river valleys and on bridge approaches. Temperatures sit in the mid-40s, and drivers are urged to build in extra travel time and stick with low beams until the fog lifts. A Dense Fog Advisory is in effect until 9 a.m. CST, with conditions expected to gradually improve after sunrise as southerly winds start to mix out the low clouds.
Fog And Morning Commute
Low clouds and pockets of dense fog are sprawled across the metro, particularly along the Mississippi and in the outer suburbs, so motorists should slow down and leave extra stopping distance. Bridge crossings and riverfront roads may be especially tricky while visibility is reduced, and short delays on bus and light-rail routes are possible. For the latest advisory and hour-by-hour updates, check NWS St. Louis.
Afternoon Storms And Wind
Once the fog finally mixes out, temperatures will surge into the upper 60s with a high near 69°F and a chance of thunderstorms from late morning into the afternoon. A few storms could produce hail or damaging gusts if they manage to strengthen, although the severe threat hinges on whether those storms can sustain themselves. This lines up with this week’s wild temperature swings from murk to mild; see our fog to warmth swings for context.
Late-Day Fire Weather Risk
By afternoon, drier air will surge in from the west, dropping humidity into the mid-20s and kicking up gusty west-southwest winds that could come close to Red Flag conditions in parts of central Missouri. While the strict Red Flag area is mainly west and northwest of the immediate metro, any outdoor burning this afternoon could spread quickly, so avoid open flames and secure loose yard debris. Expect winds to ramp up through the afternoon, with gusts commonly in the 20 to 30 mph range and higher in exposed spots.
Tonight And The Weekend
A cold front slides through Thursday night, knocking temperatures back toward seasonal norms with lows near 37°F and gusty west winds that can top 30 mph in places. Friday recovers into the low 50s before a cooler weekend settles in, with highs mostly in the 30s and 40s and only a slight chance for mixed precipitation Saturday in northern suburbs. Keep an eye on local forecasts and your commute, since conditions can pivot quickly between fog, storms, and windy, dry air.
