If the heat doesn’t get you, the foul air might.

Wildfire smoke is making it hard to breathe in metro Detroit. The Environmental Protection Agency recommends staying indoors because of the conditions outdoors. 

The EPA’s air quality index measures pollutants such as ozone, dust, and fine particles. The primary pollutant in Detroit is particulate matter that is 2.5 micrometers or less in diameter.

An index of 0 to 50 is considered good. Anything over 300 is hazardous. 

The AirNow website showed AQIs over 500 for PM 2.5 as of 9:00 a.m. EDT.

Where’s it coming from?

The Michigan Department of Environment, Great Lakes, and Energy has issued an air quality alert for the entire state. EGLE says the smoke is coming from wildfires in Canada and Minnesota.

Corey Behnke is a meteorologist at the National Weather Service office in White Lake Township. He says a shift in the jet stream is responsible.

“The jet stream that was confined to northern Canada earlier this week is now pushed down in the northern Great Lakes, just over northern Lake Huron,” he says. “This jet stream is bringing well organized northwest winds to the region.”

Metro Detroit was already dealing with heat and humidity before the smoke arrived. Behnke says the high pressure system responsible for the hot weather is starting to weaken. But that’s adding to the smoke problem.

 “As that breaks down, now we’re starting to see greater mixing throughout the atmosphere and is helping transport that smoke down to the surface,” he says.

Relief is coming

Behnke says the smoke could linger through Friday before spotty rain and milder temperatures move in for the weekend.

“There will be some rain chances beginning Friday afternoon, and then we could see rain chances again Saturday afternoon,” he says. “No widespread rain across the region, but definitely some chances for some showers and thunderstorms.”

The forecast calls for highs in the mid-80s Saturday and Sunday.

What to do

EGLE recommends these steps to protect yourself from smoke:

• Stay indoors and avoid strenuous activities.
• Wear an N-95 mask if you must be outside.
• Run forced air systems on “fan” or “cooling.” Set window air conditioners to “recirculate.”
• Limit activities that create indoor pollution such as frying foods.
• Limit outdoor activities such as campfires and using gas-powered vehicles.