What’s causing the haze in Boise, and when will it clear out?

Stagnant weather conditions have trapped local pollutants in the skies over the Treasure Valley, creating a thickening haze over Boise.

“We’ve seen a gradual building all week,” said Michael Toole, regional airshed coordinator for the Idaho Department of Environmental Quality. “It’s been kind of building slowly.”

And it’s not going anywhere soon.

The Idaho Department of Environmental Quality issued a yellow air quality alert for the next three days, through Monday. During that time, outdoor burning is prohibited in both Ada and Canyon counties, and all the cities within the two counties.

Toole said many people are asking him about whether the air quality in Boise is being impacted by California fires. Based on the smoke models he’s seen, he doesn’t think the wildfire smoke is affecting us much.

Inversion conditions in the Treasure Valley are typical around this time of year. That’s when colder air is trapped in the Valley and keeps pollutants from cars, outdoor burning and fireplaces from mixing out and dispersing.

Toole said we might see a change in the weather pattern by sometime in the middle of next week.

Katy Moeller: 208-377-6413

This story was originally published November 16, 2018 at 5:05 PM.