Salt Lake City air quality is worst in U.S. amid latest inversion

Utah needs some big winds to blow the bad air away.

(Chris Samuels | The Salt Lake Tribune) Low clouds and haze cover the tops of buildings in downtown Salt Lake City during an inversion event on Monday, Dec. 19, 2023.

Salt Lake City had the worst air quality in America as of Monday morning, and it may not get much better for several days.

According to the Utah Department of Environmental Quality, Salt Lake County’s air was considered “orange” or unhealthy for sensitive groups Monday — and it is expected to stay that way Tuesday. It could improve Wednesday, but real relief is not expected until the weekend, according to the National Weather Service forecast.

As of early Monday, Salt Lake City ranked 26th in the world for worst air quality, according to IQAir. That’s way behind No. 1 Kolkata, India, but the closest U.S. city on the list to Utah’s capital at the time was No. 56 Seattle.

[Read more: Inversion weighing you down? Where to escape Salt Lake City’s bad air]

“What we need is some wind to scour this stuff out of here,” National Weather Service meteorologist Nicole Desmet said Monday morning. “It’s possible that we get some of that tonight into tomorrow morning, but it’s going to be a question of if we get enough to move it out. … Right now, it’s not looking too great.”

There is a better chance for improvement this weekend, when the forecast calls for a stronger weather system to blow through the state.

But don’t hold your breath for a white Christmas — there’s not much precipitation in the forecast.

“There’s the slightest chance for some showers this week — possibly by Wednesday, and possibly even [Tuesday], but it’s not going to be enough to improve these conditions,” Desmet said. “There’s a more potent system forecast for the weekend, and that should usher all of this out of here.”

Although the air is murky across much of northern Utah, it’s not actually as bad as it looks. Much of what looks like fog is actually fog — water vapor. “But there are still particulate matters,” Desmet said. “Stuff that you don’t want to breathe out there.”

The level of fine particulates in Salt Lake County early Monday was measured at 36.8 micrograms (one-millionth of a gram) per cubic meter of air. The daily “safe” level is 35 micrograms per cubic meter (short-term); the annual average “safe” level is 12.

In the areas where the air quality is considered “orange,” Utahns who are in sensitive groups are urged to reduce prolonged or heavy exertion outdoors; take more breaks and do less intense activities; and watch for symptoms like coughing or shortness of breath.

According to the Utah Department of Air Quality forecast, Salt Lake and Davis counties will remain “orange” through Tuesday, then improve to “yellow” (or moderate) on Wednesday.

Box Elder, Cache, Duchesne. Tooele, Uintah, Utah and Weber counties are expected to be “yellow” through Wednesday. Carbon, Grand, Iron and Washington counties should be “green” (or good) through at least midweek.