The National Weather Service has issued an air stagnation advisory for the Tri-Cities and the rest of the Mid-Columbia from 7 a.m. today to 10 a.m. Tuesday.
Stagnant air could persist longer than that, according to the weather service.
High pressure building over the region and relatively light winds will limit the dispersion of pollutants near the ground. Patchy freezing fog also is predicted from 4 to 10 a.m. each morning through Tuesday.
Although conditions causing the air stagnation could improve briefly each day, the air quality is not expected to become significantly better.
People sensitive to air quality issues should take precautions, said the weather service.