The maps show up-to-date (UTD) air quality data for the last ten days. Data are provided by the EEA’s Member and Cooperating countries and other voluntary reporting countries.
Data are collected by each data provider and delivered to the EEA with some delay after measurement . The delay varies for each data provider. In general these data are available in this viewer 2 to 5 hours after measurement.
Data can be visualised as hourly and daily resolution. The “hour” selection shows all hourly valid data as reported by each data provider. The ”day” resolution includes both daily reported data and calculated daily average using hourly valid reported data. The viewer allows the user to only view daily averages with a minimum of 75% data coverage (at least 18 hours of valid data for a day) or view daily average regardless of the minimum number of valid hourly data.
Data can also be filtered based on the type of station and/or of area.
Under “type of station”, the stations are classified in relation to the predominant emission sources: traffic stations, industrial stations and background stations (where the pollution level is not dominated by either traffic or industry).
The classification or “type of area” describes the location with respect to the distribution/density of building. An urban area is a continuously built-up urban area, while a suburban area is characterized by contiguous settlement of detached buildings of any size mixed with non-urbanised areas. A rural area corresponds to an area which does neither fulfil the criteria of urban area nor of suburban area.).
All the hourly data is stored and displayed in UTC + 1. All daily averages calculated from hourly data are based and displayed in UTC +1. The daily aggregation is only calculated for visual display.
These data are not officially validated and/or verified by the countries and therefore should not be considered for compliance checking against air quality standards.