Annual average NO₂ levels in London 2016-2023, by location and site type
Average annual nitrogen dioxide (NO₂) levels in London have been declining in recent years. NO₂ levels at roadside sites in central London averaged 33 micrograms per cubic meter (µg/m³) in 2023, representing a reduction of 65 percent relative to 2016 levels. In 2019, the Ultra Low Emission Zone (ULEZ) was introduced in central London. Operating 24 hours a day, seven days a week, drivers of vehicles who enter this zone which do not meet ULEZ emission standards are required to pay a daily charge.
