London Borough of Hounslow Monitoring Data
Hounslow Chiswick (HS4)
Latitude: 51.492507
Longitude: -0.257252
Date Started: 26/08/1999
Longitude: -0.257252
Date Started: 26/08/1999
Inlet Height: 4 metres
Environment: Urban Background
Environment: Urban Background
Latest Data
This monitoring site data was last updated: 18/07/2025 21:00
| Parameter | Pollution Band | Concentration | Period |
|---|---|---|---|
| PM10 particulate matter (Hourly measured) | Very High (Index 10) | 167 µg/m3 (TEOM FDMS) | 24 Hour mean |
| PM2.5 particulate matter (Hourly measured) | Very High (Index 10) | 164 µg/m3 (TEOM FDMS) | 24 Hour mean |
| Nitrogen dioxide (NO2) | Low (Index 1) | 20 µg/m3 | hourly mean |
| Nitric oxide (NO) | not applicable | 10 µg/m3 | hourly mean |
| Nitrogen oxides as nitrogen dioxide (NOx as NO2) | not applicable | 35 µg/m3 | hourly mean |
| Non-volatile PM10 (Hourly measured) | No Data | 24 Hour mean | |
| Volatile PM10 (Hourly measured) | No Data | 24 Hour mean | |
| Non-volatile PM2.5 (Hourly measured) | No Data | 24 Hour mean | |
| Volatile PM2.5 (Hourly measured) (Volatile PM2.5) | No Data | 24 Hour mean |
Note: Values are based on provisional data. Data are GMT hour ending.
PM10 is measured as a running 24 hour mean, up to the current hour, and the band/index is calculated accordingly.
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