Smoke from Canadian wildfires blanketed much of the United States in August, with the Midwest and Northeast facing the heaviest and most frequent exposure. This month, the 2025 wildfire season became the second-worst season on record, according to the Canadian Interagency Forest Fire Centre (CIFFC). Since April, fires there have scorched more than 19 million acres and sent smoke hundreds of miles south. Take a look at the day-by-day smoke movement through August to see how your state may have been affected.July 27 - Aug. 2 Aug. 3 - Aug. 9Aug. 10 - Aug. 16Aug. 17 - Aug 23. As of Aug. 20, more than 611 fires remained active, with nearly two-thirds labeled as either “out of control” or “out of control and monitored” by the CIFFC. Out of control fires are expected to continue growing, while monitored fires are being observed but not actively suppressed. Canada has kept its wildfire preparedness at the highest level since late May, meaning fire activity is widespread, all available crews and equipment are deployed and international aid has been requested.Wildfire smoke carries fine particles, known as PM2.5, that can seep indoors, lodge deep in the lungs, and enter the bloodstream, according to the EPA. They pose the greatest risk to vulnerable groups and may increase the chance of heart disease and other respiratory problems.Wildfire smoke can linger in the air for weeks, especially without rain or wind to clear it, according to the Western Fire Chiefs Association. Residents can track conditions through the Air Quality Index at AirNow, which includes a fire and smoke map. NOAA also provides daily maps showing smoke spread from fires in North America. If you are in an area affected by wildfire smoke, the Centers for Disease Control and Prevention advises limiting exposure to reduce irritation. Using an air filter, avoiding activities that produce smoke, and wearing a respirator can help protect against harmful effects.PHNjcmlwdCB0eXBlPSJ0ZXh0L2phdmFzY3JpcHQiPiFmdW5jdGlvbigpeyJ1c2Ugc3RyaWN0Ijt3aW5kb3cuYWRkRXZlbnRMaXN0ZW5lcigibWVzc2FnZSIsKGZ1bmN0aW9uKGUpe2lmKHZvaWQgMCE9PWUuZGF0YVsiZGF0YXdyYXBwZXItaGVpZ2h0Il0pe3ZhciB0PWRvY3VtZW50LnF1ZXJ5U2VsZWN0b3JBbGwoImlmcmFtZSIpO2Zvcih2YXIgYSBpbiBlLmRhdGFbImRhdGF3cmFwcGVyLWhlaWdodCJdKWZvcih2YXIgcj0wO3I8dC5sZW5ndGg7cisrKXtpZih0W3JdLmNvbnRlbnRXaW5kb3c9PT1lLnNvdXJjZSl0W3JdLnN0eWxlLmhlaWdodD1lLmRhdGFbImRhdGF3cmFwcGVyLWhlaWdodCJdW2FdKyJweCJ9fX0pKX0oKTs8L3NjcmlwdD4=
NEW YORK — Smoke from Canadian wildfires much of the United States in August, with the Midwest and Northeast facing the heaviest and most frequent exposure.
This month, the 2025 wildfire season became the second-worst season on record, to the Canadian Interagency Forest Fire Centre (CIFFC). Since April, fires there have scorched more than 19 million acres and sent smoke hundreds of miles south.
Take a look at the day-by-day smoke movement through August to see how your state may have been affected.
July 27 - Aug. 2
Aug. 3 - Aug. 9
Aug. 10 - Aug. 16
Aug. 17 - Aug 23.
As of Aug. 20, more than 611 fires remained active, with nearly two-thirds as either “out of control” or “out of control and monitored” by the CIFFC. Out of control fires are expected to continue growing, while monitored fires are being observed but not actively suppressed. Canada has kept its wildfire preparedness at the highest level since late May, meaning fire activity is widespread, all available crews and equipment are deployed and international aid has been requested.
Wildfire smoke carries fine particles, known as PM2.5, that can seep indoors, lodge deep in the lungs, and enter the bloodstream, to the EPA. They pose the greatest risk to vulnerable groups and may increase the chance of heart disease and other respiratory problems.
Wildfire smoke can in the air for weeks, especially without rain or wind to clear it, according to the Western Fire Chiefs Association. Residents can track conditions through the at AirNow, which includes a fire and smoke map. NOAA also provides daily showing smoke spread from fires in North America.
If you are in an area affected by wildfire smoke, the Centers for Disease Control and Prevention limiting exposure to reduce irritation. Using an air filter, avoiding activities that produce smoke, and wearing a respirator can help protect against harmful effects.
