Smoke from wildfires and wildfires in western Canada has triggered health alerts in several cities across North America. Wildfires in the province of Alberta have displaced tens of thousands of people and devastated more than 941,000 hectares over several weeks.

“It’s definitely a mix of smoke,” Christie Tucker of the Alberta Wildfire agency said during a press conference with local media. “Many Albertans obviously cannot escape the smoke,” the official said.

“Smoke from the fires is thick in many parts of the province,” Tucker said. “But the temperatures are lower than they would be if there were no smoke covering the sun,” referring to the drop in temperature with less insolation.

Less heat, Tucker explained, “meant we saw less fire growth.” Only five new cases have been reported since Friday. On the other hand, she added, firefighters have not been able to fly planes often enough to get an accurate picture of the size and number of fires that have occurred in recent days.

The smoke left skies gray and brought out the colors of the sun at dawn and dusk in major northern and northern US cities in recent days such as Chicago, New York and Boston.

A sunset amid smoky gray skies could be seen above the Statue of Liberty at dusk yesterday in New York City. The National Weather Service said smoke from Canadian wildfires about 5,000 kilometers away was affecting New York and much of the Northeast.

SPENCER PLATT/GETTY IMAGES NORTH AMERICA/AFP/METSUL METEOROLOGY

SPENCER PLATT/GETTY IMAGES NORTH AMERICA/AFP/METSUL METEOROLOGY

Satellite images from NOAA, the US weather and climate agency, showed smoke from the fires covering more than 2.7 million square kilometres, stretching from Alberta in western Canada to the east coast of North America and the Arctic.

NOAA

Environment Canada issued warnings of poor air quality posing ‘very high risks’ to health in the cities of Edmonton and Calgary, where skies were an orange hue and the smell of smoke wafted through in the air. Residents have been asked to limit outdoor activities.

In recent years, Western Canada has been repeatedly hit by extreme weather conditions, the intensity and frequency of which have increased due to global warming. Much to the delight of firefighters battling the blazes, rain has returned to Alberta with a drop in temperature over the past few hours.