If they have not already, North Dakotans are urged to become familiar with an online tool detailing air quality in their area, as environmental officials said smoky air from expanding wildfire seasons requires more awareness.

Forecasters recently warned north-central states including North Dakota would see stretches of smoke-filled air or hazy skies due to wildfires burning in Canada.

Ryan Mills, ambient air monitoring manager for the North Dakota Department of Environmental Quality, said until recently, the state would not see winds pushing smoke here until deeper in June or early July but things have changed.

“The last few years, we’ve been seeing this kind of tick-up right away in May,” Mills said. “It’s kind of like we’ve had to expand our fire season, if you will.”

His office does not track the root causes of longer and more destructive wildfire seasons but researchers said climate change is a factor. When conditions surface, the website and mobile app AirNow.gov provides up-to-date information on local air quality. Residents, especially those with respiratory issues, are urged to limit outdoor activities.

Mills advised when there’s an air quality alert and you can start to smell the smoke, it is time to block spaces where the air can seep into your house.

“Closing your windows, things of that nature,” Mills said. “Obviously, don’t be going in and out.”

Other tips include adjusting the settings on air conditioners or vehicle vents to recirculate indoor air. Online maps and other tools are often color coded to further illustrate how safe it is to be outside for long periods. When colors such as orange, red and purple come into play, it means the air quality has worsened.