Wildfires have forced an evacuation of Yellowknife, the capital of Canada’s Northwest Territories. 

Officials with the territorial government told residents in the highest-risk areas to evacuate immediately. Other residents have until 12 p.m. local time on Friday to leave the city of about 20,000.

Depending on smoke conditions, those leaving by car will be escorted through the active fire zone, officials said. Residents who can’t leave by road are being asked to register for evacuation flights.

The fires were about 17 kilometers from the city, Shane Thompson, the territory’s environment minister, told reporters Wednesday evening. “Without rain, it is possible it will reach the city outskirts by the weekend,” he said. 

For some, it will be the second exodus in recent days. Evacuees from the remote communities of Hay River and Fort Smith were already being housed in Yellowknife, according to an update Tuesday. 

Yellowknife is about 1,400 kilometers north of Edmonton, Alberta. 

Canada is experiencing the worst wildfire season on record. More than 1,000 active fires are burning across the country of which more than 670 are out of control, according to the Canadian Interagency Forest Fire Centre. So far, 13.7 million hectares have burned, far exceeding the 1995 record of 7.1 million hectares.