Dual impacts of wildfire emissions severely degrade air quality across the United States.
Canadian Wildfires Cause Major Air Quality Degradation Across North America
The ongoing wildfire season in Canada is causing significant issues for air quality across broad regions of both Canada and the United States. As of early August 2025, Canada is experiencing its second-worst wildfire season on record, with over 500 active wildfires, many of which are out of control, mainly in Manitoba, Saskatchewan, Alberta, and other provinces. These wildfires have burned through approximately 72,000 square kilometers, an area roughly the size of New Brunswick.
The widespread smoke from these wildfires has severely impacted air quality across large parts of Canada—from the Northwest Territories to Ontario—and extended into the northern and eastern United States, including the Upper Midwest and Northeast. Multiple Canadian provinces and at least 11 U.S. states have issued air quality alerts due to unhealthy levels of fine particulate matter (PM2.5), which originates from black carbon in wildfire smoke and poses serious risks for cardiovascular and respiratory health.
Cities like Detroit have experienced some of the worst air quality globally during this period. The smoke has caused hazy skies, reduced visibility (to as low as 200 meters in Fort McMurray, Alberta), and high Air Quality Health Index (AQHI) levels indicating very high health risks in affected areas.
In the United States, air quality alerts continue for states from Minnesota through the Northeast due to drifting smoke, while western states including Nevada, Utah, Colorado, and Wyoming remain on alert for new fires due to dry conditions and winds. The Gifford Fire in California, the state's largest wildfire of the year, has burned through more than 82,000 acres since igniting on Friday and has become a major concern for air quality in Southern California and Nevada.
The Gifford Fire's behavior has been extreme, burning through an area about the size of a football field every 2 seconds on average Sunday night into Monday morning. Smoke from the Gifford Fire has affected air quality in parts of Southern California and Nevada, including Las Vegas, where air quality on Monday was the worst since February 2023.
Smoke from wildfires in the western US has also decreased air quality in multiple states, especially in Southern California. The Dragon Bravo Fire in Arizona, raging along the North Rim of the Grand Canyon, has grown to one of Arizona's largest in history and has contributed to the commingling of smoke with the Monroe Canyon Fire and the Dragon Bravo Fire, which has spread into portions of Colorado, Wyoming, and New Mexico.
The smoke near the surface in the affected regions will start to clear out on Wednesday, but smoke higher in the atmosphere could linger for much of the week. Evacuation orders are in effect for portions of Santa Barbara and San Luis Obispo counties due to the Gifford Fire. The West will remain the major wildfire hot spot through at least September, according to forecasts from the National Interagency Fire Center.
It's important to note that high-level smoke has less of an impact on air quality but keeps the sky hazy and can enhance sunrises and sunsets. However, wildfire smoke contains very dangerous, tiny pollutants called PM2.5 that can lead to breathing problems and aggravate health conditions like diabetes and heart disease.
The weather that fuels wildfires—dry air and strong winds—is occurring more frequently in parts of Canada and the US, making the situation more challenging to manage. The ongoing wildfire season is expected to persist in the coming days based on current weather and fire activity, and it's crucial for individuals to stay informed and take necessary precautions to protect their health during this time.
- The wildfire-related smoke causing air quality degradation is a consequence of climate change and environmental science.
- Air quality alerts due to wildfire smoke have become common, as weather forecasting predicts a persistent wildfire season, exacerbated by weather conditions.
- Environmental science, climate change, weather forecasting, and weather-related wildfires should all be taken into account to mitigate health risks and protect the environment.
