Saskatoon and areas to the east and northeast are under an air quality alert because of smoke from forest fires burning near Hudson Bay.
Terri Lang, a meteorologist with Environment and Climate Change Canada, said winds are pushing smoke from the fires through the northern grain belt this afternoon and evening.
"The fires in the Hudson Bay area came back to life and they're spewing out quite a bit of smoke," Lang said. "Because of the direction of the upper winds, that's bringing the smoke back into the central areas of the province and it's drifting over the Saskatoon area now."
Areas affected include Saskatoon, Rosthern, Delisle, Wakaw, Hudson Bay, Melfort, Nipawin, Humboldt and Lanigan.
"The worst part of the day [in Saskatoon] will probably be in the next few hours into the evening as the smoke sort of fumigates down to the surface," Lang said Monday afternoon. "Overnight the plume itself will start to lift northward, and by tomorrow morning we should see some improvement."
People who have breathing difficulties, or who have lung diseases such as asthma and COPD, are being told to stay indoors.
Inhaling smoke can cause symptoms such as increased coughing, throat irritation, headaches or shortness of breath.
Lang said hot, dry conditions are contributing to prolonging the fire season.
"[Sunday] the temperatures were in the mid 20s C, which is really above average for this time of year. Our average highs at this time are around 14 C," Lang said. "The other contributing factor is it's very, very dry out there and that's contributing to these fires sort of getting going again."
Lang said there is also a risk of grass fires right now.
"Until we start getting more moisture coming, which doesn't look like it will be for a while, there's that risk of grass fires going so people should be particularly cautious."
The smoke is expected to slowly drift northward.
"The alerts for those areas closest to where the fire is occurring will continue," Lang said. "And because the plume of smoke itself is moving to the north, the areas in the North Battleford and the Prince Albert region might start to see it, as well as it might start drifting toward Meadow Lake, Waskesiu, those areas tomorrow."