Light snow was reported in a few scattered areas overnight and Tuesday morning, including West Seattle, Spanaway, Carbonado, Sequim and other locales.
In other areas, the main problem was black ice on the roadways and freezing temperatures during the early morning hours - especially in the Cascade foothills, the Kitsap Peninsula and the Everett area northward.
In Whatcom County, subfreezing winds gusting up to 35 mph out of the Fraser River Valley pushed the wind chill down to 15 degrees at around 8 a.m.
School delays also were reported in the Oakville, Ocosta, and North Beach school districts.
By 11 a.m., temperatures in the Puget Sound lowlands were mostly in the 30s under sunny skies.
The National Weather Service warned that temperatures around much of Western Washington including the main Seattle urban corridor will fall below freezing each night through the end of the week. Daytime temperatures aren't expected to reach much above freezing.
In a special statement, the Weather Service said the cold weather will likely continue through Monday of next week. Temperatures toward the end of the period will be similar to or even slightly colder than those expected the next couple days.
Renewed arctic winds out of the Fraser River Valley may also produce cold wind chills across Whatcom County and the San Juan Islands later in the week.
Another weather system may bring a chance of snow late this weekend or early next week.
This is a developing news story. More information will be posted as it becomes available.