Radon is everywhere but some parts of Britain have higher levels than others. We call these areas “radon hotspots”.
The quickest and easiest way to know if you are in a radon hotspot area is to access the Interactive Map on the UKHSA’s UKRadon website at the link below.
Please note the map is of probabilities only. It is not a substitute for actual radon measurements. The map is divided into 1km2 blocks. The database behind the interactive map comprises numerous historical passive radon measurements at domestic addresses in each 1km2 block. Each 1km2 block is designated a “maximum radon potential” colour code. The logic of the designation is to assign the colour for the whole 1km2 block based on the highest individual measurement within that 1km2 block. It is therefore quite a generalisation, especially in highly populated areas.
https://www.ukradon.org/information/ukmaps
The map is simple to use. Firstly enter your postcode which will display your immediate postcode block area, suitably colour coded. Press “Show Radon Data” to show the Legend of the colour coding. You can Zoom in or out using the 
keys:
