Beginning in May 2026, Europe was confronted with a historic heat wave which has lingered into the early months of summer. It’s the worst heat wave on record to-date as temperatures soared to 42°C (108°F) across part of Western, Central, and Southern Europe (1). It’s the second severe heat wave in a year; in 2025, at least 95% of Europe broiled beneath above-average annual temperatures (2).
Scientists are attributing more frequent and intense in European heat waves to climate change (3)(4). The health risks extend beyond the heat itself. Extreme temperatures are intertwined with air pollution, as stagnant air traps pollutants like ground-level ozone and particulate matter. Wildfires and dust storms, both intensified by prolonged heat, can also contribute to poor regional air quality. As a result, severe, prolonged temperatures can significantly impact air quality and consequently impair health across the continent.
How heat waves form
A heat wave is prolonged period of unusually excessively hot weather (5). Heat waves may also coincide with high humidity.
Heat waves are most common in summer months but can be experienced at any time of year, including winter (6). They may begin with high-pressure systems that act like invisible domes, trapping hot air near the surface. These systems bring clear, calm conditions that allow the sun to persistently heat the ground while stagnant air prevents the heat from dispersing. This creates a self-reinforcing cycle: the longer the system lingers, the more the air and land temperatures climb.
Why Europe is vulnerable to heat waves
Europe’s geography can have an intensifying effect on heat waves. The Mediterranean Sea, currently warming 20% faster than the global ocean average, fuels humidity and heat wave intensity in southern regions (7). The continent’s dense urban corridors can also create urban heat islands that amplify temperatures.
Increasing arctic ice melt can fail to mix with ocean saltwater, resulting in too much freshwater in the North Atlantic (8). This in turn can lead to an increase in warmer water in the North Atlantic and changes to the atmospheric jet stream, sometimes forming double jet streams. Double jet streams are strongly linked to European heat waves, as they can create a zone of weak winds, which in turn can create blocking high-pressure systems (or anticyclones) (9). Increasingly disrupted by climate change, jet streams can lock these high-pressure systems in place for weeks, baking parts of Europe under prolonged, extreme heat.
Even home design can contribute to how Europeans experience indoor heat. Concrete homes, common across Germany, are built to help retain heat in cold winters. Heat built up during the day can then be released once again into back into the home at night (10). Coupled with the fact that only about 20% of European homes have air conditioning, this can make for sleepless, hot nights (11).
The science of heat waves and air pollution
Heat waves contribute to air pollution in several meaningful ways.
First, heat domes occur with stagnant atmospheric conditions, preventing pollutant dispersal. These conditions can trap exhaust, smoke, and industrial emissions close to the ground where people breathe them.
The combination of intense sunlight and high temperatures accelerates the chemical reactions that produce ground-level ozone, the main ingredient in smog.
Meanwhile, the dry, hot conditions can dry out ground cover and generate ideal conditions for wildfires and dust storms to flourish. Smoke and dust can then carry PM2.5 and PM10 – particulate matter measuring 2.5 and 10 microns or less in diameter respectively – into the air.
Health and environmental impacts
Extreme heat and polluted air can create an unhealthy synergy that impacts the human body. Vulnerable groups, including children, older adults, athletes, outdoor workers, pregnant women, people without air conditioning, and people with pre-existing conditions face the greatest health risks during a prolonged heat wave (12)(13).
When inhaled, PM2.5 can enter the bloodstream and be carried to every part of the body. This tiny pollutant has been linked to cardiovascular and respiratory disease. When paired with high heat the effects on human health can be significant.
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Short-term health effects:
- Increased respiratory distress
- Heat exhaustion
- Heatstroke
- Acute cardiovascular strain
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Long-term health effects:
- Chronic lung disease
- Reduced cardiovascular health
- Premature death
Europe’s ecosystems also suffer during heat waves and poor air quality events, with impacts that ripple across agriculture, wildlife, and local communities (14).
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Short-term environmental effects:
- Immediate stress on crops, livestock, forests
- Increased wildfire risk
- Spikes in dust-related events that degrade air and soil quality
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Long-term environmental effects:
- Persistent ecosystem damage, including drier rivers and lakes
- Reduced agricultural productivity from drier soils
What can be done
Heat waves combined with air pollution pose a serious challenge to Europe’s health and environment. There are solutions that can help reduce the risks.
What governments can do
- Strengthen and enforce air quality standards to hold industries and vehicles accountable for their emissions.
- Invest in renewable energy and public transportation to reduce reliance on climate change accelerating fossil fuels and private vehicles.
- Expand air quality monitoring networks to provide real-time data and inform targeted interventions.
- Promote regional cooperation to address transboundary pollution, such as industrial emissions and crop burning, particularly with non-EU countries with less restrictive burn regulations.
What communities can do
- Support and participate in local initiatives to raise awareness about air pollution and its health impacts.
- Advocate for stronger policies and better enforcement to protect vulnerable populations.
What individuals can do
- Choose sustainable transportation options, such as walking, cycling, or using public transit, to reduce personal contributions to air pollution.
- Use air purifiers and wear high-quality masks on high-pollution days to limit exposure.
- Stay informed with free real-time air quality information to make healthier daily decisions.
The takeaway
Europe’s heat waves and air pollution are intertwined phenomenon that build upon one other. Stagnant air traps pollutants and extreme heat and accelerates smog formation; this feedback loop can have further knock-on effects which impact both human health and fragile ecosystems.
As these events grow more frequent and intense, further mitigation to reduce the worst impacts of climate change and limit air pollution can help safeguard human health. Adaptive policies, public awareness, and decisive climate action may help disrupt this cycle and protect more communities across the continent.
