Around 30,000 people were under orders Saturday to evacuate their homes in western Canada's British Columbia, provincial officials said, as a raging wildfire bore down on the city of Kelowna.

"The situation is highly dynamic and the numbers are changing all the time, but as of now we are currently hovering at about 30,000 people on evacuation order and an additional 36,000 people on evacuation alert," said Bowinn Ma, British Columbia's minister of emergency management and climate readiness.

Kelowna, a city of 150,000, was choked with thick smoke as it became the latest population center hit in a summer of dramatic wildfires across Canada that has left millions of acres scorched.

"We cannot stress strongly enough how critical it is to follow evacuation orders when they are issued," Ma said at a news conference.

"They are a matter of life and death not only for the people in those properties, but also for the first responders who will often go back to try to implore people to leave."

Premier David Eby gave slightly different figures for the number of evacuees across the province, saying 35,000 people had been ordered to leave with 30,000 told to prepare to flee if needed.

Authorities urged thrill-seekers to stay away, as their presence could disrupt the work of firefighters and first responders.

Eby and Ma also announced an emergency order seeking to halt non-essential visits to the area.

The order, which bans visitors from checking in at hotels and other temporary accommodations, covers Kelowna and the nearby towns of Kamloops, Oliver, Penticton and Vernon as well as Osoyoos near the US border.

"Please just stay out of these areas if you don't have to be there," Eby said.

The evacuation came one day after the Northwest Territories capital of Yellowknife was emptied in the largest ever evacuation from the region.

Winds have been fanning wildfires towards Yellowknife, but overnight rain brought some relief Saturday with a sharp dip in temperatures, government weather forecasts showed.