South Dakota roads may look merely damp this morning, but a thin, nearly invisible hazard is making travel risky across the region. Pavement frost has formed in spots along and east of Interstate 29, creating slick conditions just as fog begins to thin.
According to the National Weather Service in Sioux Falls, dense fog is slowly eroding, but temperatures remain below freezing, allowing moisture to freeze directly onto road surfaces. This setup is especially common during calm winter mornings when cold pavement meets moist air.
The highest risk stretches from eastern South Dakota into southwestern Minnesota and northwestern Iowa, including Sioux Falls-area corridors, rural highways, and untreated roads. Bridges, overpasses, and shaded stretches cool faster overnight and remain slick longer than surrounding pavement.
Drivers may notice frost forming even where no precipitation has fallen. Vehicles can lose traction suddenly, particularly when braking or turning. The danger is amplified by lingering fog, which reduces reaction time and masks icy patches.
Conditions should gradually improve later this morning as temperatures inch upward and fog fully clears. Until then, the Monday commute remains a concern, especially for school buses, early workers, and anyone traveling at highway speeds.
Motorists are urged to slow down, increase following distance, and avoid hard braking. If tires begin to slide, easing off pedals helps maintain control. Checking road conditions before leaving remains critical, even if streets appear clear.
This type of pavement frost is a classic Winter 2026 hazard, arriving quietly and disappearing quickly, but not before causing spin-outs and crashes.
Five-Day Outlook (Sioux Falls Region):
- Monday: Fog early, patchy pavement frost
- Tuesday: Dry, colder morning
- Wednesday: Clouds increase
- Thursday: Watching next system
- Friday: Seasonably cold
