Key facts
- Sadiq Khan triggered the alert on advice from Imperial College London forecasters, his office said.
- The mayor's office said smoke from Bonfire Night and Diwali fireworks and from wood burning likely contributed.
- The mayor's office said it is the fourth high air pollution alert issued in London in 2026.
- Alerts are displayed on bus stop countdown signs and on the Underground, the mayor's office said.
- The mayor's office said information was shared with London's GPs and emergency departments for vulnerable patients.
- Deputy mayor Mete Coban said toxic air is responsible for thousands of premature deaths in London each year.
Sadiq Khan, the mayor of London, triggered a high air pollution alert for Tuesday, November 10, 2026, after forecasters at Imperial College London advised him to issue it, his office said.
High levels of particle pollution were forecast for Tuesday after dense fog and very light winds allowed pollution to build up over the weekend and linger into Monday morning. The mayor's office said smoke from Bonfire Night and Diwali fireworks, as well as wood burning, likely contributed. It said the alert is the fourth high air pollution alert issued in London in 2026.
City Hall issues alerts to Londoners, schools and London boroughs when moderate, high or very high air pollution is forecast. The mayor's office said alerts are displayed at public locations across London, including all bus stop countdown signs and on the Underground, and that information was shared with London's GPs and emergency departments to help them support vulnerable patients.
The mayor encouraged Londoners to walk, cycle or use public transport where possible, avoid unnecessary car journeys and refrain from burning wood or garden waste. Mete Coban, the deputy mayor for environment and energy, said: "Toxic air is responsible for thousands of premature deaths in London each year, which is why the Mayor has done everything in his power to tackle it, which includes launching the world's largest clean air zone."