Air quality

Cleaning London's air

Every child in London deserves to breathe clean air. Together with the Mayor, Sadiq Khan, we are committed to reducing the impact of polluting road vehicles.

Air quality advice

We have air quality advice for each level of daily air pollution.

London's air quality - how bad is it?

The volume of road traffic in London makes it one of the most polluted places in the UK - an estimated 5.8 million journeys are made by car every day.

Air pollution is not just a central London problem - many areas across the city still exceed the legal limits for pollution. Pollution is now returning to pre-coronavirus pandemic levels across the Capital.

How road transport harms our air

Road vehicles are the main cause of London's air pollution. They produce around half of all nitrogen oxides and emit tiny particles - like small bits of rubber and metal - into the air we breathe.

These harmful gases and particles can pass through the nose and throat, enter our bloodstream and harm our organs. This contributes to thousands of early deaths each year and increases people's risk of heart and lung disease and asthma.

Air quality myth #1

Myth: Only central London is affected by air pollution

FACT: Pollution affects every borough in the city, not just central London

Air quality myth #2

Myth: Road vehicles aren't the main cause of London's air pollution

FACT: Driving polluting vehicles is the single biggest cause, contributing to around half of the air pollution in London

Children are particularly vulnerable to the effects of poor air quality. The lung capacity of children in inner London is about 10% smaller than normal for this age.

Air quality myth #3

Myth: You don't need to switch off a car engine when stationary

FACT: Research shows that turning off the engine significantly reduces pollution levels in the surrounding area

Air quality myth #4

Myth: You can always see when air pollution is bad in London

FACT: Most airborne toxins are invisible to the naked eye

What we're doing for air quality

We're helping to clean London's air by, for example, running the Ultra Low Emission Zone (ULEZ) in central London, cleaning up our bus fleet and taxis, and supporting small businesses and charities to switch to cleaner vehicles.


  • In 2019 we introduced the world's first 24-hour Ultra Low Emission Zone (ULEZ) in central London. The ULEZ has contributed to a 44% reduction in roadside nitrogen dioxide within its boundaries
  • From 25 October 2021, the ULEZ will extend up to the North and South Circular Roads, creating a much larger zone that will help improve air quality for millions of Londoners
  • We're introducing tougher Low Emission Zone standards for lorries, buses and coaches from 1 March 2021 within Greater London
  • We're cleaning up London's bus fleet, creating one of the greenest fleets in the world. Currently over 95% of the bus fleet meets Euro VI emissions, the highest emissions standards
  • We have over 370 zero-emission buses in the fleet and over 3,800 hybrid buses. All buses in central London meet the Euro VI emissions standards or are electric buses which are zero emission at tailpipe. We aim to have a zero emission bus fleet no later than 2037
  • All new licensed taxis in London must be zero-emission capable - more than 3,700 already operate in the Capital
  • We're committed to installing at least 300 rapid charge points for electric vehicles by December 2020 - over 270 are already installed

Healthier streets

Today's forecast: Low

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Tomorrow's outlook: Low

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For more information on local pollution, visit the London Air website.

This air quality information is provided by King's College London.