Where smoke from Canadian wildfires has spread into the U.S.

As dozens of wildfires continue to burn across Canada, flames are sending far-reaching plumes of smoke into the sky and unhealthy air to distant places. Some of the more gigantic blazes have been delivering thick smoke that spread southward into the United States over recent days.

The fires are burning from British Columbia, through Alberta and Saskatchewan to Manitoba and Ontario - with several between 100,000 and 300,000 hectares apiece. More smoky skies are expected as this week begins, although the smoke is not expected to be as thick as it’s been in recent days.

» READ MORE: Wildfire smoke can have lingering health effects for everyone

Prime fire season in Canada is just beginning, though already about half a year’s worth of land has been scorched, according to the long-term average.

At least 25,000 people were evacuated from three Canadian provinces by the weekend, according to the Associated Press. Manitoba alone accounted for 17,000 of the evacuations.

Two fires there have burned well past 100,000 hectares (247,000 acres), the largest of which has scorched 189,834 hectares (469,090 acres) on the border with Ontario, about 65 miles northeast of Winnipeg. Several fires around Flin Flon, in the western portion of the province on the border of Saskatchewan, are responsible for most of the evacuations.

Just west, in the province of Saskatchewan, it has already become the worst fire season in decades.

The Shoe Fire alone has grown past 300,000 hectares (741,000 acres). While burning largely in rural forest, several communities nearby remain under evacuation orders, among 20 towns forced from their homes in the province.

Orange-tinged skies spread much further than the poor surface air. Carried by the river of air in the sky called the jet stream, smoke ended up as far south as the coastal Southeast U.S. over the weekend.

Skies turned hazy as far south as northern Florida. It was particularly thick over portions of the Midwest, holding high temperatures down several degrees despite sunshine.

In North Dakota and adjacent Canada, visibilities dropped as low or a mile or so as smoke drifted toward the ground. Far removed from the fires, Bismarck, North Dakota, experienced haze and one-to-two-mile visibility much of Saturday.

With time, building high pressure in the east should shunt the smoke trajectory back to the north and focus on Canada.

Air quality alerts stretch from parts of British Columbia in Canada’s west to Ontario south of Hudson Bay. In the harder-hit portions of northern Alberta and Saskatchewan into Manitoba, Environment Canada is warning residents to limit time outside and reschedule or cancel outdoor events.

The forecast south of the border Monday has much of Minnesota, Wisconsin and surrounding locations under a code orange alert. A zone around Milwaukee may see code red conditions.

There is an air quality alert for Minneapolis and the rest of the state. The Minnesota Pollution Control Agency warns that particulate levels will be unhealthy for sensitive groups, or those with lung disease, heart disease, as well as children and the elderly.

Michigan’s Upper Peninsula is also under an air quality alert and has red flag warnings for a local fire threat.

It comes on the heels of bad air over the weekend for parts of the Plains and Upper Midwest in addition to adjacent Canada. A large portion of North Dakota registered a daily average of very unhealthy air Saturday. On Sunday, code red conditions shifted east to include parts of Minnesota.

Wildfires in Canada have already burned about half of what was average before the major fire seasons in 2023 and 2024.

That translates to more than 1.1 million hectares (2.7 million acres) blackened this year so far. Before the historic season in 2023 - in which 17.3 million hectares (42.7 million acres) were scorched - the average for a year was 2.1 million hectares.

Fires in the region are being enhanced by dry conditions, including zones of moderate drought, according to the North American Drought Monitor.

While some rain appears in the forecast ahead, it probably won’t be enough to change the overall situation heading into summer.

Peak fire season is usually June to August or September in Canada.