A stage 1 burn ban was called for Pierce County on Thursday.
Puget Sound Clean Air Agency said calm winds and cold nights likely will result in pollution levels that are unhealthy for sensitive groups.
A stage 2 burn ban is in place for Snohomish County.
Under a stage 1 burn ban, no burning is allowed in wood-burning fireplaces, uncertified wood stoves or uncertified fireplace inserts unless it is the only adequate source of heat.
All outdoor burning is prohibited, including wood and charcoal-fueled fires.
The last burn ban in Pierce County was canceled Monday after being in place for several days.
With clear, cold weather returning, so has the burn ban.
Nighttime temperatures are forecast to be in the low 30s this week.
Stacia Glenn: 253-597-8653