Wildfire smoke spreads to Canada, East as northwestern US fires multiply
Wildfires ignited by lightning are expanding across the Northwest as heat and drought persist, sending smoke across the northern and eastern U.S. and southern Canada and raising concerns over dangerous air quality.
Video from Wheeler County, Oregon, shows firefighters battling the lightning-sparked Rowe Creek Complex Fire on July 26. The fire has burned more than 209,000 acres of land so far.
Tinder-dry conditions, extreme heat and lightning strikes have fueled an uptick in wildfires across eastern Washington, eastern Oregon and Idaho in recent days. At the same time, fires continue to burn across parts of southern Canada. The growing fires threaten nearby communities, and their smoke is expected to worsen air quality across portions of the United States and Canada.
Large, active fires on the map are depicted as flame symbols as of Tuesday, July 28, 2026. Smaller active or recent fires appear as small dots or squares. (Source: National Interagency Fire Center).
"Many of the lightning-caused fires were sparked during the North American monsoon thunderstorms that were most active over the past week," AccuWeather Meteorologist Brandon Buckingham said.
Persistent heat and parched vegetation will allow the fires to spread this week despite containment efforts in areas where crews have been able to respond safely.
Many of the thunderstorms produced little rainfall while locally gusty winds helped newly ignited fires spread rapidly.
"One particularly active period occurred from July 22 to July 23, when more than 8,300 lightning strikes were detected in Oregon alone," Buckingham said.
Dozens of large fires burning from Oregon and Washington to Idaho and western Montana are producing thick smoke that is significantly degrading air quality across the region. Southwesterly winds are carrying some of that smoke into south-central Canada.
Meanwhile, fires in interior British Columbia are sending smoke through the Canadian Rockies and into Alberta.
Some of the smoke has risen high into the atmosphere, where the jet stream is carrying it. While the fast-moving winds help disperse the smoke, they also transport it across southern Canada and the northern tier of the central United States. As the jet stream dips near the Great Lakes, some of the smoke loops back into parts of the eastern U.S.
This image, taken on Tuesday, July 28, 2026, captures much of the northwest and north-central United States and adjacent areas of Canada and shows thick smoke (wispy gray) from the northern Rockies to the southern Canadian Prairies. Less dense, high-flying smoke can be seen near the Great Lakes region, intertwined with cloud cover. (AccuWeather RealVue™ Satellite)
"There are still fires burning in western Ontario, but recent rainfall has reduced the size and intensity of some of the fires, limiting the amount of smoke reaching the Midwest and Northeast," Buckingham said. "Most of the remaining smoke from these fires and the ones in the northwestern U.S. is staying high in the atmosphere, creating hazy skies rather than poor air quality at ground level."
Even so, some smoke may mix down to ground level in parts of the East, depending on atmospheric conditions, potentially affecting air quality for sensitive groups.
The ongoing hot weather pattern will continue to promote wildfire growth while sporadic monsoon thunderstorms, many of which produce little rainfall, will increase the risk of additional lightning-caused fires.
Later this week and this weekend, a potent Pacific storm is forecast to sweep into the Northwest. Instead of widespread soaking rain, it may bring gusty winds and another round of mainly dry thunderstorms, increasing the risk of additional wildfire starts across parts of the Northwest and British Columbia.
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