Patchy fog and frost tonight, mostly sunny Sunday

SEATTLE - A beautiful Saturday with plenty of sunshine and chilly temperatures. 

Overnight we will see the return of dense fog and frost. Temperatures will cool into the upper 20s and low 30s.

Areas of fog will linger through mid-morning before more sunshine in the afternoon. 

Highs will stay below average, only topping out in the upper 40s to low 50s. 

High pressure continues Sunday and into the first half of the workweek. This is creating air stagnation concerns because of the poor mixing and cold temperatures.  A Burn Ban is in effect for Snohomish County. 

For those heading over the mountain passes, no major problems with clear and dry conditions. It will also be dry and cold for the Seattle Marathon. 

Morning fog and mostly sunny skies in the afternoon through midweek. Rain chances return Thursday with most likely rain Friday into Saturday.