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EIR - ULEZ Second year air quality change [Aug 2025]

Key information

Request reference number: MGLA070825-1806

Date of response:

Summary of request

Your request 

  1. What was the level of nitrogen dioxide (NO2) across all of London estimated to have been in the second year of the expansion of the Ultra Low Emission Zone (Ulez)?
  2. What was the change in air quality in the second year of the expansion of the Ultra Low Emission Zone (Ulez)?
  3. Can you please provide estimates for particulate matter 2.5 (PM2.5) in outer London in the second year of the expansion of the Ultra Low Emission Zone (Ulez)?
  4. Please provide any other statistics held for levels of pollutants in the second year of expansion of Ulez?

Our response

The ULEZ expanded London-wide on 29 August 2023. The London-wide ULEZ One Year Report provides an extensive analysis of the impacts of the first year of the London-wide ULEZ (September 2023 – September 2024) and provides detailed summary tables of the data for readers. The report, as well as the supporting data, is available on the GLA website via the following link: London-wide Ultra Low Emission Zone One Year Report | London City Hall

We have not replicated this data analysis for time period requested (September 2024 – September 2025) and therefore do not hold information within scope of this request.
You can find air pollutant concentrations (including nitrogen dioxide) for the period requested publicly available online. All data from the reference air quality monitors in London are publicly available on either the London Air (London Air Quality Network) or Air Quality England (Air quality in England) websites, depending on which data manager the borough subscribes to. These websites include the monitor locations and dates they have been running, as well as all the pollution concentration data, which can be freely downloaded.

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