Please note: In our daily air quality heat maps, you can use the EU or the DEFRA AQI health thresholds based on hourly AQI measurements. For each day, hourly AQI values are assessed, and the highest hourly AQI reading is selected to represent that day’s value. This is shown on the top row of the chart. This ensures that the daily AQI reflects the worst air quality conditions experienced during the day, providing a clear and consistent measure for comparison across different days and locations. Enjoy!
DEFRA AQI Heatmaps
By introducing DEFRA AQI–based heat maps, you will be able to:
- Rapidly identify high-pollution days and their primary pollutant sources.
- Benchmark local air quality against DEFRA health standards in a transparent way.
- Use visual evidence to support community engagement, compliance reporting, and resource prioritisation.
- Additional AQI’s will follow in due course.
Where to find DEFRA Heatmaps drop down
Please view the Heatmap widget
This could be a default widget or a saved view or found in the widget library
There is a drop-down menu (shown in the blue box below) at the top of the widget where you can select the AQI you wish to analyse.
Simply select DEFRA to update the Heatmap data using the appropriate AQI.
Heatmaps allows you to…
- Quickly identify high-pollution days and the pollutants driving the exceedance.
- Provide clear, evidence-based insights to stakeholders, public health directors, and community groups.
- Benchmark local air quality against DEFRA standards and demonstrate compliance or areas of concern.
- NO2, o2, PM10 and PM2.5 are available for analysis
This helps by…
- Current pollutant concentration data is complex and time-consuming to analyse. This is quick and easy.
- Difficult to clearly communicate findings to non-technical audiences. This makes it very easy to visualise and understand.
Key benefits of DEFRA Heatmaps
- Intuitive visualisation of daily AQI and corresponding pollutants.
- AQI bands based on DEFRA AQI for consistency and regulatory alignment.
- Exportable format as JPEG for easy onward reporting and presentation use.
- Adaptive time periods, with flexible views from 1 week to 1 year.
Enjoy!