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Latest air quality summary
Number of monitoring sites in each pollution band
Heathrow Airwatch was last updated at 17:00 on Tuesday 20th April 2021
- Low22
- Moderate0
- High0
- Very High0
- No Data3
- 25
Total monitoring sites





London Hillingdon

Parameter | Pollution Band | Concentration | Period |
---|---|---|---|
Ozone (O3) Updated: 20/04/2021 16:00 |
Low (Index 3) | 73 µg/m3 | 8 Hour mean |
Oxides of Nitrogen (NOXasNO2) Updated: 20/04/2021 16:00 |
not applicable | 24 µg/m3 | hourly mean |
Nitrogen dioxide (NO2) Updated: 20/04/2021 16:00 |
Low (Index 1) | 20 µg/m3 | hourly mean |
Nitric Oxide (NO) Updated: 20/04/2021 16:00 |
not applicable | 2 µg/m3 | hourly 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.