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Latest air quality summary
Number of monitoring sites in each pollution band
Heathrow Airwatch was last updated at 14:00 on Saturday 27th July 2024
- Low20
- Moderate0
- High0
- Very High0
- No Data2
- 22
Total monitoring sites
![Green](http://www.heathrowairwatch.org.uk/images/map_legend_1-3.jpg)
![Orange](http://www.heathrowairwatch.org.uk/images/map_legend_4-6.jpg)
![Red](http://www.heathrowairwatch.org.uk/images/map_legend_7-9.jpg)
![Purple](http://www.heathrowairwatch.org.uk/images/map_legend_10.jpg)
![Grey](http://www.heathrowairwatch.org.uk/images/map_legend_0.jpg)
London Hillingdon Harmondsworth Os
![Maximum pollution level at this monitoring site is Index 1](images/dials/ap_1.gif)
Parameter | Pollution Band | Concentration | Period |
---|---|---|---|
PM2.5 Particulate matter (PM2.5) Updated: 27/07/2024 05:00 |
Low (Index 1) | 7 µg/m3 (Osiris) | 24 Hour mean |
PM10 Particulate matter (PM10) Updated: 27/07/2024 05:00 |
Low (Index 1) | 14 µg/m3 (INDIC GRAV) | 24 Hour mean |
Note: These results are based on provisional data. The data are presented in graphical form based on the highest pollutant measured at each site.