The London Air Quality Network website contains information about air quality in and around Greater London. Measurements are collected either hourly or twice daily from continuous monitoring sites, processed and checked then placed on this web site with an hourly update.
There is a wealth of information here, showing pollution levels across London as a map and as a graph, where levels are monitored and how each location compares to health standards and targets. There is also a description of the latest pollution episodes, a facility for calculating advanced statistics or plotting your own graph and access to a number of relevant reports.
Use your mouse and keyboard to select wanted items from drop down lists and then press buttons to get what you want.
You can often click on images or words that have been underlined to do things - try it and see what happens. There are a number of menu links at the top of every page. If you get lost, use one of these or click on 'home' go back to the home page and start again.
If you are from a local authority these specific pages may help direct you.