Smoke continues to linger in the region from wildfires in Canada.
The National Weather Service says the Air Quality Alert will now continue through Thursday at noon.
They say weather conditions will keep a dry stable air mass over Western Washington through at least Thursday.
For the interior lowlands of Western Washington air quality has gradually deteriorated since Sunday and many sensors are now reporting marginal to poor air quality.
According to the weather service conditions will continue to transport smoke into Western Washington from wildfires in British Columbia through at least Wednesday.
In addition, atmospheric ventilation in the interior lowlands of Western Washington will remain poor.
They say a weak low level onshore flow will continue to bring better air quality to the coast.
The smoke and hazy skies will continue to plague Western Washington for the next few days but a change to southwest flow late Thursday could start to push the smoke out of the area.
Until the smoke clears people with respiratory problems should limit outdoor activity if possible.