Seattle air quality worsens by 30 points in 30 minutes as smoky haze descends

Seattle's air index quality has reached an unhealthy level for sensitive groups as hot temperatures and smoky skies loom over Puget Sound.

The city's air quality index rose 30 points half an hour on Thursday, from a "moderate" 81 to 104.

The smoke comes from wildfires in British Columbia, Canada, according to the Washington Smoke Information blog. Smoke from the California fires are expected to drag up smoke from the southern region.

The poor air quality joins forces with heat. The temperature is predicted to be in the low 90s on Friday, and potentially near 100 in some areas of the Puget Sound region.

An AQI above 101 is considered unhealthy for sensitive groups, like the elderly, children, and those with lung and heart disease.

(As of 4:30 p.m., the AQI was 118. Parts of eastern Washington registered above 250.)

Sensitive groups should wear a mask outdoors and close open windows in their home to protect themselves from air pollution.

Seattle's air quality forecast is expected to stay at a moderate pollution level through Friday.