Mayor of London issues high pollution alert
The Mayor of London, Sadiq Khan, has triggered a ‘high’ air pollution alert for London tomorrow, Friday 6 March 2026.
Forecasters at Imperial College London advised the Mayor to issue the alert due to a likelihood of high levels of Particulate Matter, caused by a combination of Saharan dust and pollution drifting in from continental Europe towards London.
Pollution levels are expected to be highest overnight and early on Friday after which stronger winds will help disperse the accumulated pollution.
This is the first high air pollution alert this year. Additional details have been shared with London’s healthcare professionals - GPs and emergency departments, to ensure that they have crucial information to help vulnerable patients.
City Hall issues alerts to Londoners, schools, and London boroughs when moderate, high or very high air pollution is forecast. High air pollution alerts are also displayed at public locations across London, including all bus stop countdown signs, as well as on the Underground.
The Deputy Mayor for Environment and Energy, Mete Coban said: “Toxic air is responsible for around 4,000 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.
“We are urging Londoners to look after themselves in this high pollution period, stop their engines idling, and refrain from burning wood or garden waste – all of which contribute to high levels of pollution. This is particularly important in order to protect the most vulnerable as we continue building a safer and greener London for everyone.”
Notes to editors
· Particulate Matter (PM) is a transboundary pollutant and therefore concentrations are heavily influenced by meteorology, background concentrations and sources outside of London, including on the continent, on top of local emissions.
· The moderate and high daily thresholds are based on Defra’s national Daily Air Quality Index (DAQI).
· These thresholds are nearly two and a half times higher than the World Health Organization (WHO) recommended limits for exposure and represent especially acute exceedances which can have immediate health impacts for individuals with pre-existing conditions such as asthma or Chronic obstructive pulmonary disease (COPD).
· In 2016, the Mayor set up a system to warn Londoners about moderate and high pollution episodes. These forecasts are created by Imperial College London, and checked against other public forecasts (airTEXT, Met Office, London Air) to predict when air pollution in the capital will reach moderate, high or very high levels.
· In 2024, the Mayor expanded the alerts system coverage to also go to NHS GPs and Emergency Department consultants, in order to support the health and care system across London in advising vulnerable patients.
· More information about the alerts can be found here: https://www.london.gov.uk/programmes-and-strategies/environment-and-climate-change/pollution-and-ai…