This article has been updated to reflect and extension of the air quality advisory, and additional details about impacted areas.

Eastern Colorado is under an air quality advisory which has been extended until at least 9:00 a.m. Saturday due to smoke from wildfires burning in Canada.

The Colorado Department of Public Health and Environment issued the advisory due to moderate to heavy smoke. CDPHE recommends that people with heart or lung disease, older adults, and children should reduce prolonged or heavy exertion.

Similar alerts are in place for Montana, as well as portions of Washington, Idaho and Wisconsin. Related weather statements for air quality have been issued for portions of Wyoming and Nebraska.

According to CBC/Radio-Canada, 100 wildfires are burning across Alberta and have forced thousands of people to evacuate their homes. Dozens of provincial parks and recreation areas are closed as Canadians head into the Victoria Day holiday weekend.

At least 29 additional fires are burning in neighboring Saskatchewan.

More than 100 firefighters from the United States are assisting in efforts to contain the fires.

Environment Canada lists air quality statements for nearly all of Alberta, along with portions of British Columbia, Saskatchewan, Manitoba, Yukon, and Northwest Territories.

So far this year, nearly 500 wildfires have burned 802,571 hectares (1,983,196 acres) in Alberta, roughly 8,026 square kilometers or 3,099 square miles – an area more than twice the size of Kiowa County, Colorado. That compares to 805,900 hectares (1,991,422 acres) for all of 2011, and 883,441 hectares (2,183,030 acres) in 2019.