Daily Air Quality Index (DAQI)
Ten-point scale for pollution levels
The Daily Air Quality Index runs from 1 to 10 and reports short-term pollution. It covers nitrogen dioxide, sulphur dioxide, ozone, PM2.5 and PM10, and the worst single pollutant sets the whole index. Defra publishes it on advice from the Committee on the Medical Effects of Air Pollutants. All four UK nations use the same scale.
What This Means
The figure on this report is a modelled estimate for the area around this property. It is not a live reading at the front door. Pollution varies street to street, so a road frontage can sit worse than a garden behind. The index also moves day to day, and one number cannot describe a whole year. Nobody buys or sells a house on a single day's pollution reading. Long-term exposure is the question that matters for a home, and the annual pollutant readings against UK limits answer it. This index does not.
Score Ranges
Low
1 to 3Pollution is low. Everyone can carry on with their usual outdoor activities.
Moderate
4 to 6Adults and children with lung or heart problems may want to ease off strenuous outdoor activity.
High
7 to 9Anyone with a lung or heart condition, and older people, should reduce strenuous exertion outdoors.
Very High
10Everyone should reduce exertion outdoors, and at-risk groups should avoid it altogether.
Practical Advice
- Check the Defra UK-AIR forecast for this postcode across a still winter week, when urban pollution peaks.
- Ask the council's environmental health team for recent readings from the monitoring station named on this report.
- Ask your GP how to manage asthma or a heart condition here if the band reads High or Very High.
- Compare the annual pollutant figures in this section against the UK limits shown beside them.
Key Points
- Ozone runs higher in open countryside than in city centres, so a rural address can band High on a hot day while a city nearby reads Moderate.
- A DAQI of 4 and a DAQI of 6 both read Moderate, though 6 sits one point off the High band.
- Very High days are rare, and usually come from a summer ozone episode or still winter air trapping traffic fumes.
Additional Information
The report names the nearest monitoring station and its distance. Station type matters: a roadside station reads higher than an urban background station a few streets away. Neither may sit on this road, and the modelled figure fills the gap between them.