This map was build to allow Sensor.Community users to find the best location for a new sensor
according to researchers in the Netherlands.
They are currently building a correction algorithm based on
the measurements both of official stations and citizen sensors in a radius of 250 m or 1000 m.
You can
look for your city or your street in the search engine and then zoom in or zoom out to set the map
correctly.
At the relevant zoom levels, the circles appear to indicate the amount of sensors in the radii
of the official stations.