AURN Monitoring Site Monitoring Data
London Westminster (HORS, an AURN site)
Latitude: 51.494670
Longitude: -0.131931
Date Started: 17/07/2001
Longitude: -0.131931
Date Started: 17/07/2001
Altitude: 5 metres
Environment: Urban Background
Environment: Urban Background
Latest Data
This monitoring site data was last updated: Sorry, no current data available. The last data date time is: 05/11/2025 24:00
| Parameter | Pollution Band | Concentration | Period |
|---|---|---|---|
| Ozone (O3) | Low (Index 1) | 32 µg/m3 | 8 Hour mean |
| Nitrogen dioxide (NO2) | Low (Index 1) | 25 µg/m3 | hourly mean |
| PM2.5 particulate matter (Hourly measured) | No Data | 24 Hour mean | |
| Nitric oxide (NO) | not applicable | 1 µg/m3 | hourly mean |
| Nitrogen oxides as nitrogen dioxide (NOx as NO2) | not applicable | 27 µg/m3 | hourly 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.