Persistent smoke from roaring wildfires in the West continues to haunt Utah residents, leaving people complaining of respiratory issues and chasing them indoors.
Although the smoke is not nearly as bad as it was Friday and through the weekend, the National Weather Service in Salt Lake City says a building high pressure and a return to hotter temperatures will keep haze on the doorstep of the Wasatch Front.
The weather service is predicting triple-digit temperatures to return on Friday, with a high of 100 degrees and then a slight drop into the high 90s for Salt Lake City on Saturday and Sunday.
The levels of PM2.5, or fine particulate matter, remain at unhealthy levels and above the federal threshold of 35 micrograms per cubic meter.
Salt Lake County sat at 40 as of 10 a.m. Tuesday, while Utah County measured 46.6.
Those tiny particles (a human hair is 70 times larger) are inhaled into the lungs where they cause damage, particularly to vulnerable populations such as the very young, the elderly or those with compromised respiratory systems.
Those particles are also linked to increased incidence of stroke and heart attacks.
Top pulmonary experts in Utah warned Friday that exposure to these kinds of concentrations of PM2.5 is unhealthy for everyone and people should avoid being outdoors if at all possible.
Although the fine particulate matter is typically what Utah experiences in excess during winter inversions, this smoke-caused buildup of pollution behaves differently and is unhealthier because of the chemicals it contains.
The smoke comes from an unprecedented fire year for the western United States.
More than 100 large wildfires are burning in 15 states in the West, with California experiencing its second largest fire in its history.
The Dixie Fire has burned more than 480,000 acres. At least 890 structures have been destroyed in a blaze that is just 25% contained.
Much of the western United States, including Utah, is suffering from extreme drought. The dry conditions and triple-digit temperatures make it ripe for record-setting wildfires.