Updated July 22, 2026 — NASA has released a day-by-day visualization showing how smoke from Canadian wildfires crossed large parts of the United States and Canada from July 14 through July 20.

The animation uses brown carbon as a tracer for organic particles emitted by wildland fires. NASA says the data come from its GEOS modeling system, which combines satellite, aircraft and ground observations with weather information to estimate how smoke moves through the atmosphere.

The model shows smoke moving from Ontario into the Upper Midwest, Northeast and Mid-Atlantic. NASA reported that air quality ranged from unhealthy to hazardous in cities including Detroit, Toronto, Chicago, New York and Washington during parts of the period. Conditions later improved in some eastern areas as storms cleared the air, while smoke began affecting parts of the Pacific Northwest.

The visualization is a model-based reconstruction, not a neighborhood-level air-quality reading. People should use the EPA AirNow map or local health authorities for current conditions. Fine-particle pollution from smoke can aggravate heart and respiratory illness, and high concentrations can affect otherwise healthy people.

The new NASA analysis adds a verified geographic and scientific record to the earlier reporting on smoke impacts and the U.S.–Canada policy dispute. It does not resolve how long the fires or cross-border smoke episodes will continue.

Source: NASA Earth Observatory — science.nasa.gov source ↗

Source: NASA Scientific Visualization Studio — svs.gsfc.nasa.gov source ↗

Source: U.S. EPA AirNow Fire and Smoke Map — airnow.gov source ↗