Wildfires and Heat Waves Put Global Air Quality at Risk, UN Weather Agency Warns
Rising Heat and Wildfire Smoke Create a Growing Global Health Threat
The world is facing a growing air-quality challenge as increasingly intense wildfires and prolonged heat waves threaten to reverse progress made in reducing pollution, the World Meteorological Organization (WMO) has warned.
In its latest annual assessment of air quality and climate, the United Nations weather agency said climate change and air pollution are closely connected. According to the WMO, governments can no longer treat climate change, extreme weather and air pollution as separate problems because developments in one area can significantly affect the others.
The warning comes as several regions have experienced extreme heat and destructive wildfires. Smoke from major fires can travel hundreds or even thousands of kilometres, meaning communities far away from the original fire can also experience unhealthy air.
Wildfires Are Becoming a Major Source of Air Pollution
Wildfires release large quantities of smoke and fine particles into the atmosphere. One of the most concerning pollutants is fine particulate matter known as PM2.5.
These extremely small particles can penetrate deep into the respiratory system and are associated with serious health risks, including respiratory and cardiovascular problems.
WMO scientific officer Lorenzo Labrador warned that even areas that normally enjoy relatively clean air can experience deteriorating conditions when smoke from large wildfires reaches them.
This creates a difficult challenge for countries that have already introduced measures to reduce pollution from vehicles, factories and other sources. Improvements in those areas can be undermined when extreme wildfire activity produces large amounts of additional pollution.
Heat Waves Can Make Air Pollution Worse
Wildfires are not the only concern. Extreme heat itself can contribute to worsening air quality.
The WMO says heat waves are becoming more frequent, intense and longer-lasting as global temperatures rise. Hot conditions can also contribute to the formation of ground-level ozone, another pollutant associated with health problems.
The combination of extreme heat and wildfire smoke can therefore create particularly difficult conditions for communities already dealing with high temperatures.
Smoke Can Travel Across Borders
One of the biggest challenges highlighted by the warning is that wildfire pollution does not remain close to the location where a fire begins.
Strong winds and atmospheric conditions can transport smoke across large distances. As a result, cities and communities hundreds of kilometres away can suddenly experience hazy skies and deteriorating air quality.
This means that protecting air quality requires cooperation between regions and countries rather than relying only on local pollution-control measures.
Recent Regions Have Experienced Elevated Pollution
The WMO report pointed to several areas where PM2.5 concentrations in 2025 were above long-term averages, including northern Canada, parts of Russia and west-central Africa, where increased fire activity contributed to higher pollution levels.
Northwestern Spain was also identified as a pollution hotspot following exceptional late-summer wildfires.
Europe has also experienced destructive fires and extreme heat in countries including Spain, France and Greece, highlighting the growing challenge faced by communities during periods of severe weather.
Health Risks Are a Major Concern
Poor air quality can affect people in different ways. Exposure to fine particles and other pollutants can aggravate respiratory problems and increase cardiovascular risks.
Children, older adults and people who are particularly sensitive to air pollution can be among those most vulnerable when smoke levels rise.
The WMO highlighted the importance of understanding wildfire pollution because smoke contains a complex mixture of particles and chemicals. Researchers cited in the report have also found that extreme wildfire-smoke events have increased substantially over recent decades.
WMO Calls for Better Monitoring and Early Action
The UN weather agency says stronger monitoring systems are needed to understand how pollutants move through the atmosphere.
The report also highlights the need to improve monitoring of aerosols and pollutants such as black carbon and microplastics, which remain less thoroughly tracked than some other pollutants.
Better monitoring can help authorities identify dangerous conditions earlier and provide timely warnings to communities affected by smoke and extreme heat.
Climate and Air Pollution Policies Need to Work Together
A central message from the WMO is that climate policy and air-quality policy should not be developed in isolation.
Reducing greenhouse-gas emissions can help address the long-term drivers of climate change, while stronger air-quality measures can reduce people's exposure to harmful pollution.
The agency warns that more frequent extreme wildfires could make it increasingly difficult for countries to meet World Health Organization air-quality guidelines.
A Warning for the Future
The latest assessment presents a clear challenge for governments, scientists and communities.
As temperatures rise and extreme weather becomes more disruptive, protecting clean air will require stronger forecasting, improved pollution monitoring, effective wildfire preparedness and coordinated climate action.
The WMO's warning also demonstrates why air quality is not simply a local environmental issue. Smoke can cross borders, extreme heat can influence pollution chemistry, and events in one region can affect people far beyond the original source.
Conclusion
The growing combination of wildfires and heat waves is putting additional pressure on global air quality, according to the World Meteorological Organization.
While progress has been made in reducing pollution from some traditional sources, increasing wildfire activity and extreme heat could make future improvements more difficult.
The WMO's message is that climate change and air pollution must be addressed together. Better monitoring, stronger early-warning systems and coordinated policies will be increasingly important in protecting public health and maintaining cleaner air in a warming world.