Automatic Urban and Rural Network (AURN) - DEFRA UK Air

Introduction

The AURN is the UK's largest automatic monitoring network and is the main network used for compliance reporting against the Ambient Air Quality Directives. It includes automatic air quality monitoring stations measuring oxides of nitrogen (NO _x ), sulphur dioxide (SO ₂ ), ozone (O ₃ ), carbon monoxide (CO) and particles (PM ₁₀ , PM _2.5 ). These sites provide high resolution hourly information which is communicated rapidly to the public, using a wide range of electronic, media and web platforms.

What is measured?

The table of parameters lists everything measured since the AURN network started, and is not necessarily what the network is measuring at this current time.

Parameters Measured	Monitoring sites and data	Current sites: 196 Total sites: 308 Data availability: 01/07/1972 to 17/07/2025

Ozone
Nitric oxide
Nitrogen dioxide
Nitrogen oxides as nitrogen dioxide
Sulphur dioxide
Carbon monoxide
PM ₁₀ particulate matter (Hourly measured)
Non-volatile PM ₁₀ (Hourly measured)
Volatile PM ₁₀ (Hourly measured)
PM _2.5 particulate matter (Hourly measured)
Non-volatile PM _2.5 (Hourly measured)
Volatile PM _2.5 (Hourly measured)
PM ₁₀ particulate matter (Daily measured)
PM _2.5 particulate matter (Daily measured)
Daily measured PM ₁₀ (uncorrected)
Daily measured PM _2.5 (uncorrected)
Modelled Wind Direction
Modelled Wind Speed
Modelled Temperature

What is the purpose of the network?

The major objectives of the network are as follows:

Checking if statutory air quality standards and targets are met;

Informing the public about air quality;

Providing information for local air quality review and assessments within the UK Air Quality Strategy;

Identifying long-term trends in air pollution concentrations; and

Assessing the effectiveness of policies to control pollution.

The data from the AURN are used for:

Compliance reporting under the Air Quality Standards Regulations 2010

Comparison with air quality objectives as laid out in the Air Quality Strategy

Providing the public with information through air quality bulletins

Forecasting future air quality levels

Policy development for human health and ecosystem protection

The European Monitoring & Evaluation Programme (EMEP)

The UK Local Air Quality Management regime under Part IV of the Environment Act 1995

National Indicators on environmental quality

How is the network run?

A number of organisations are involved in the day-to-day running of the network. Currently, the role of Central Management and Co-ordination Unit (CMCU) for the whole AURN is contracted to Bureau Veritas , whilst Quality Assurance and Quality Control (QA/QC) activities are contracted to the National Physical Laboratory for London ( the ALN ), and Ricardo Energy & Environment for the rest of the AURN. The responsibility for operating individual monitoring sites is assigned to local organisations, such as local authority Environmental Health Officers with relevant experience in the field. Calibration gases for the network are supplied by BOC Limited and are provided with a UKAS certificate of calibration by Ricardo Energy & Environment.

Annual reports can be viewed in the Library section.

Monitoring Methods

The techniques used for monitoring within the AURN are summarised ( on the monitoring methods page of this website ).

The interactive map page provides an interactive view of this network with links to site information and latest data.

Data Verification and Ratification

The following PDF is available: The Data Verification and Ratification Process (PDF) which contains more information about the data verification and ratification process.

Current and Closed AURN monitoring sites

To view the current monitoring sites within the AURN, view the current levels page which also shows the parameters measured.

Information about closed AURN sites is also available for reference purposes.

Select an AURN monitoring site from the dropdown below to view the associated site information.

Select site:

View data for sites in this network

You can view the latest data from this network on the Latest pollution summary page.

Data can be downloaded from the Data Selector section of this website.

Automatic Urban and Rural Network (AURN)

Automatic Hydrocarbon Network

Automatic London Network

Locally-managed automatic monitoring

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View latest data for the AURN

Download data for this network from the Data Archive

View interactive map for this network

All content is available under the Open Government Licence v3.0, except where otherwise stated.