In July 2024, wildfires in Canada intensified due to intense heat, winds, and storms, leading to 989 active fires, primarily in British Columbia and Alberta. NASA’s GEOS-FP model showed significant movement of smoke across North America by tracking the spread of soot particles. Strong winds, record temperatures, and lightning strikes created optimal conditions for these wildfires, leading to new fires and evacuations, especially in Jasper National Park. Bitter rain clouds pushed the smoke further into the atmosphere, worsening air quality in many U.S. states.

The effects of wildfires and smoke in Canada

In July 2024, wildfires in Canada caused smoke to spread across North America. Extreme heat combined with windy conditions and thunderstorms contributed to the fires starting and spreading across many Canadian provinces. According to the Canadian Interagency Wildfire Centre, as of July 24, there were 989 actively burning fires in Canada, more than half of which were in British Columbia and Alberta.

The animation below shows the concentration and movement of wildfire smoke from July 17–24, 2024. It shows sooty carbon particles (commonly called soot) from the Canadian wildfires that covered large areas of North American skies during this period. Black carbon from fires in Oregon and Washington is also visible.

The black carbon data comes from NASA’s GEOS Advanced Processing (GEOS-FP) model, which assimilates data from satellites, aircraft, and ground-based observing systems. In addition to using satellite observations of aerosols and fires, GEOS-FP also incorporates meteorological data such as air temperature, humidity, and wind to predict smoke behavior.

Wildfires increase in British Columbia and Alberta

Wildfire activity in British Columbia and Alberta increased during the period shown in the animation as unstable weather conditions moved into the region. Strong winds and storms, along with record-high temperatures in some places, created perfect conditions for wildfires. The British Columbia Fire Service reported 20,000 lightning strikes on July 21 and 38,000 on July 22, with most of these strikes occurring in the northeastern part of the province, with the rest in the south-central part.

The storms caused dozens of new fires and numerous evacuations from cities and public lands. Smoke from hundreds of active fires drifted across the country and south into the central United States. Smoky skies and poor air quality were reported in many states, including North Dakota, Kansas, Colorado and Wisconsin.

Fires in Jasper National Park

According to media reports, multiple fires in Alberta’s Jasper National Park forced as many as 25,000 visitors and residents to flee the area on July 23. The above image, taken that day by the Visible Infrared Imaging Radiometer Suite (VIIRS) radiometer on the NOAA-20 satellite, shows a thick plume of smoke rising from these fires.

Stormy rain clouds

Along the southern edge of the plume, remnants of a pyrocumulus rain cloud, or pyroCb, can be seen. These tall, smoggy thunderclouds lift the plume high into the atmosphere, where strong upper-level winds can spread it over a wide area. According to Michael Fromm, a meteorologist at the U.S. Naval Research Laboratory, there was a brief pyroXB 70 minutes before this image was taken. During this outbreak, scientists discovered several more