AURN Monitoring Site Monitoring Data
London Westminster (HORS, an AURN site)
Date Started: 17/07/2001
Environment: Urban Background
This monitoring site data was last updated: 09/12/2023 11:00
|Ozone (O3)||Low (Index 3)||72 µg/m3||8 Hour mean|
|Nitrogen dioxide (NO2)||Low (Index 1)||18 µg/m3||hourly mean|
|PM2.5 particulate matter (Hourly measured)||Low (Index 1)||6 µg/m3 (BAM)||24 Hour mean|
|Nitric oxide (NO)||not applicable||2 µg/m3||hourly mean|
|Nitrogen oxides as nitrogen dioxide (NOx as NO2)||not applicable||21 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.