Environment Canada has issued air quality statements for parts of central, southwest and northeast Saskatchewan.
Smoke from forest fires in northern Saskatchewan continued drifting into nearby areas to the south and southwest Thursday.
Prince Albert, La Ronge, Pelican Narrows and Kamsack were among the affected communities, with Environment Canada warning of reduced visibility on roads and extremely poor air quality.
The weather service said winds were expected to shift throughout Wednesday, gradually pushing smoke back toward northern Saskatchewan.
People in the affected areas were advised to stay indoors if they have breathing problems. The statement warned that poor air quality could cause increased coughing, throat irritation, headaches or shortness of breath.
The statement went on to note that children, seniors and those with cardiovascular or lung diseases, such as asthma, were especially at risk.