A cold air inversion over the Pacific Northwest is causing air to stagnate over the region, making air pollution levels to be an ongoing concern.
National Weather Service forecasters said a weather change is not likely until next week.
An air stagnation advisory was extended from Friday to 4 p.m. Monday, and wood burning bans and limits continue to be in place.
Sunshine had been forecast during daytime hours, but fog over the region this morning has been stubborn to dissipate. Fog is an increasing possibility at night.
At 7 a.m., it was 20 at Spokane International Airport and 28 at 2 p.m.
After today, highs are expected to be in the middle to upper 30s with lows in the 20s.
Air quality was moderately polluted in Spokane from wood smoke, indicating wide compliance with the burning restrictions.
However, a monitoring site at Broadway Elementary School reported a pollution level this morning above 100 on the air quality index, which is considered unhealthful for persons with respiratory or other problems and may result in a violation of federal clean air standards, officials said.
The monitor reading dropped to 96 this afternoon, on the high end of the moderate range.
The Spokane Regional Clean Air Agency sent inspectors to the area looking for improper burning. Their first approach is to contact residents and explain to them the problem and the need for compliance with burning rules, said Ron Edgar, chief of technical services for the clean air agency.
The agency is continuing its ban on outdoor burning and a partial ban on indoor burning. Residents are allowed to use certified, cleaner-burning stoves and inserts, but not open-flame fireplaces and uncertified appliances.
North Idaho also has a ban on all outdoor burning, and a request that residents voluntarily curtail the use of wood heating methods.
All outdoor burning has been banned in Eastern Washington.
Officials are encouraging residents with cleaner-burning devices to make sure they operate their appliances properly by getting a hot fire started with dry wood and heating up the device before limiting air flow.
“I think people are doing pretty well,” Edgar said.
Stoves and inserts built since the late 1980s meet federal requirements for cleaner burning.
Higher air pressure continues to dominate the region’s weather, causing cold air layers to form near the ground, preventing pollutants from dispersing.
A dry system on Sunday may help clear the air, and the next wave of low pressure is due into the region by mid-week, bringing a small chance of light snow around Tuesday night or Wednesday.