Wednesday's balmy spring-like day is expected to give way to the return of valley rain and mountain snow late Thursday.
The National Weather Service forecast called for rain showers in the Salt Lake and Tooele valleys by afternoon, though high temperatures still will climb into the upper-50s, just a few degrees cooler than Wednesday's expected high.
By Thursday evening, those showers could turn into full-fledged thunderstorms that will stretch into early Friday.
Southern Utahns should escape the precipitation, though, with partly cloudy skies and daytime highs in the low 70s.
The Utah Division of Air Quality rated breathability as "green," or healthy statewide.