Mother Nature has put the chill on our warm weather recently—in Seattle, highs have cooled to near-average the past few days—and now, things are about to get downright frosty.
With a cold air mass spreading south over Western Washington, the first widespread frost of the season is expected tomorrow night into Saturday morning as temperatures dip to the freezing mark.
Frost was already seen early this morning in some parts of the metro area as clear skies allowed the mercury to drop into the lower- to mid-30s. (Sea-Tac Airport, for one, bottomed out at 34 degrees—the coldest reading there since last March.) It’s important to realize that, because the ground is a little colder than the air right above it during the overnight hours, frost is often observed with temperatures in the mid 30s—since thermometers are generally located about five to six feet above the surface. Actual ground temperatures, of course, will always be 32 degrees or less whenever frost is present.