What is a red flag warning? What to know about dangerous weather alert

More than 400 wildfires burned across Canada on Tuesday, 238 of them considered out-of-control. The smoke has made its way to the U.S., resulting in unhealthy air quality levels and eerie, hazy sunrises.

Fire danger is poised to strike in parts of the U.S. as well, with the National Weather Service listing parts of Michigan as under a red flag warning for Wednesday after five states were listed at risk on Tuesday If your area is under such an alert, here's what it means and what to do about it.

The weather service issues a red flag warning when there is an increased risk of fire danger because of warm temperatures, low humidities and strong winds. It's especially important for fire managers and officials – red flag warnings let them know to stop any planned burns and keep an eye out for wildfires.

Red flag warnings are typically issued during the spring and fall fire seasons, the weather service says, which is Feb. 15 to April 30 and Oct. 1 to Dec. 15.

According to the International Association of Fire Chiefs and the weather service, residents can protect their homes from fire danger by following these guidelines:

The IAFC also recommends keeping grass and vegetation short and watered before a red flag warning to keep your home safe from fires.

There aren't specific guidelines against grilling during a red flag warning, but you’ll want to exercise more caution than normal if you do. Drier conditions mean embers or sparks from outdoor fires can easily ignite leaves or grass.

If you are planning to grill, do not leave the grill unattended and dispose of ashes and charcoal properly by soaking them in water and throwing them in a metal can.

Just one state (Michigan) was under a red flag warning on Wednesday after five states were under such conditions Tuesday, including parts of Pennsylvania, New Jersey, Michigan, Washington and Alaska. See USA TODAY's interactive map of weather warnings, air quality index and wildfire smoke map for the U.S. and Canada.

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