Outdoor burning has been banned in North Idaho through Wednesday because of stagnant air conditions caused by a layer of cold air at lower elevations.
The ban is in effect for Boundary, Bonner, Kootenai, Shoshone and Benewah counties. It does not include indoor residential burning, but officials are asking residents to burn cleanly.
Air quality had slipped into the moderate range today, officials said.
In Spokane, air quality deteriorated from the good to moderate range this morning, but indoor burning was being allowed.
The National Weather Service has extended an air stagnation advisory through 10 a.m. Wednesday for all of Eastern Washington and North Idaho. Higher air pressure in the upper atmosphere has caused colder air to become trapped below 3,000 feet in elevation in a temperature inversion that is typical during periods of calm weather in the winter.