An air quality alert for the region has been extended until noon Friday as wildfire smoke remains at unhealthy levels.

Air quality in Yakima was at hazardous levels Monday morning, and it was worse in the Lower Yakima Valley. It is expected to remain at unhealthy levels this week, according to forecasts from the state Department of Ecology and the National Weather Service.

The Yakima-area weather forecast Monday called for a 20% chance of showers Monday night and Tuesday, along with areas of smoke. Smoke and haze are expected to remain through at least Friday, according to the latest forecast.

The smoke is coming from large wildfires in Washington and Oregon. An expected break from a weather system didn’t materialize Monday, according to the state’s smoke forecasters.

“To add to our woes, light southerly winds will continue for another day at least, dragging more smoke directly from Oregon fires northward along the I-5 corridor,” a report from the Department of Ecology said Monday. “So even if the ubiquitous smoke pool from offshore starts to erode a bit, a replacement is en route.”

As of 1 p.m. Monday, the air quality index for Yakima was 388. For Toppenish, it was 470. And for Sunnyside, it was 446, according to the Department of Ecology. A rating of 50 or less means good air quality. A rating of 300 or more indicates air quality is hazardous.

While most schools in the Yakima Valley are taking place online this fall, the hazardous conditions did prompt some changes. Riverside Christian School, Christ the Teacher Catholic School and St. Joseph Marquette canceled classes Monday. La Salle High School and Central Washington University went online only.

What to do

People should stay indoors and keep indoor air clean by closing windows and doors when smoke is at unhealthy levels.

Other tips from the state Department of Health:

Set air conditioners to recirculate.

Avoid burning candles and incense, smoking, broiling or frying foods and vacuuming, as these can add to indoor pollution.

Use a portable air cleaner with a HEPA filter or build your own with a box fan and air filter.

Wildfire smoke can affect anyone, but young children, older adults and those with heart and lung disease are at greater risk for health problems. People with heart or lung issues such as asthma should make sure they are taking medications as prescribed and contact a health care provider with any questions.

For updated smoke information, go to wasmoke.blogspot.com.