Hungarian air quality index

The Hungarian Air Quality Index allows users to understand more about air quality where they live, work or travel. Displaying up-to-date information for Hungary, users can gain insights into the air quality in individual regions and cities. The Index is based on concentration values of pollutants listed below:

·       Benzene (C6H6);

·       Carbon monoxide (CO);

·       Nitrogen dioxide (NO2);

·       Ozone (O3);

·       Particulate matter (PM10);

·       Fine particulate matter (PM2,5);

·       Sulphur dioxide (SO2);

It reflects the potential impact of air quality on health, driven by the pollutant for which concentrations are poorest due to associated health impacts. The index is calculated hourly for 58 fixed air quality monitoring stations and 2 mobile stations, using up-to-date data reported Hungarian Air Quality Network.

These data are not formally verified and must be used only for information purposes.

Hungarian legislation sets air quality standards for both short-term (hourly or daily) and long-term (annual) air quality levels. Standards for long-term levels are stricter than for short-term levels since serious health effects may occur from long-term exposure to pollutants. The Index indicates the short-term air quality situation. It does not reflect the long-term (annual) air quality situation, which may differ significantly.

The air quality index is not a tool for checking compliance with air quality standards and cannot be used for this purpose.


The Index uses up to date air quality data reported every hour by Hungarian Government Offices. Concentrations values determine the index level that reflects air quality at each monitoring station. The index corresponds to the poorest level for any of the pollutants, according to the table shown below. Circles on the map represent the locations of air quality monitoring stations. The colours reflect air quality at the given hour at that station.

Stations missing data for certain pollutants

To avoid leaving out stations that do not report data for all pollutants or for which missing, the index is calculated for all monitoring stations with data for at least one pollutant. Those stations that do not report data at all, the index is not calculated and the station is coloured as grey. Grey dots indicate stations for which no data have been reported for 3 days. After this time the station will not appear on the map.

Averaging time for pollutants

For CO, NO2, O3 and SO2, hourly concentrations are fed into the calculation of the index. For benzene (C6H6), PM10 and PM2.5, the 24-hour running means for the past 24 hours are fed into the calculation of the index. A 24-hour running mean will be calculated if there are values for at least 18 out of the 24 hours.

Bands of concentrations and index levels

The bands are based on the relative risks associated to short-term exposure to PM2.5, O3 and NO2, as defined by the World Health Organization in its report on the Health Risks of Air Pollution in Europe project (HRAPIE project report).

The relative risk of exposure to PM2.5 is taken as basis for driving the index, specifically the increase in the risk of mortality per 10 µg/m3 increase in the daily mean concentration of PM2.5.

Assuming linearity across the relative risks functions for O3 and NO2, we calculate the concentrations of these pollutants that pose an equivalent relative risk to a 10 µg/m3 increase in the daily mean of PM2.5.

For PM10 concentrations, a constant ratio between PM10 and PM2.5 of 1:2 is assumed, in line with the World Health Organization´s air quality guidelines for Europe.

For SO2, the bands reflect the limit values set under the EU Air Quality Directive.

Pollutant Index level
(based on pollutant concentrations in µg/m3)
  Excellent Good Moderate Poor Very poor Extremely poor
Particles less than 2.5 µm (PM2.5) 0-10 10-20 20-25 25-50 50-75 75-800
Particles less than 10 µm (PM10) 0-20 20-40 40-50 50-100 100-150 150-1200
Nitrogen dioxide (NO2) 0-40 40 - 90 90-120 120-230 230-340 340-1000
Ozone (O3) 0-50 50-100 100-130 130-240 240-380 380-800
Sulphur dioxide (SO2) 0-100 100-200 200-350 350-500 500-750 750-1250


Air quality measurements that exceed the maximum values in the “extremely poor” category are not taken into account for the index calculation, since these values are typically found to be erroneous.

Health messages

The index bands are complemented by health related messages that provide recommendations for both the general population and sensitive populations. The latter includes both adults and children with respiratory problems and adults with heart conditions.

AQ index General population Sensitive populations
Excellent The air quality is good. Enjoy your usual outdoor activities. The air quality is good. Enjoy your usual outdoor activities.
Good Enjoy your usual outdoor activities Enjoy your usual outdoor activities
Moderate Enjoy your usual outdoor activities Consider reducing intense outdoor activities, if you experience symptoms.
Poor Consider reducing intense activities outdoors, if you experience symptoms such as sore eyes, a cough or sore throat Consider reducing physical activities, particularly outdoors, especially if you experience symptoms.
Very poor Consider reducing intense activities outdoors, if you experience symptoms such as sore eyes, a cough or sore throat Reduce physical activities, particularly outdoors, especially if you experience symptoms.
Extremely poor Reduce physical activities outdoors. Avoid physical activities outdoors.


Additional information

When clicking on a station on the map, a pop-up window appears with the following additional information:

1.   The name of the station.

2.   The air quality index of the main pollutants at that station over the last 3 days. The last colour shows the actual index.

3.    On the “Air Quality” subpage the last hourly concentration data can be seen. This data cannot be seen on the main website.

4.   “Further data” links the measurement data of the automatic network.

Attention! On the “Air Quality” subpage in the pop-up window the values indicate the last hourly concentrations for all components. The index reflects the hourly concentrations for CO, NO2, O3 and SO2 and the 24 hour running means for C6H6 (benzene), PM10 and PM2.5 . There may be a case for these pollutants where the index shows worse or better air quality than the hourly value.

Further information

Further information on air quality:

-          Under „Measurement data”: up-to-date air quality measurement

-          Under „Evaluations”: air quality statistics, diagrams and maps for the main pollutants

-          Under „Information”: information on the air quality network, air quality zones, AQ index and legislation

The European Air Quality Index – which is the base of the Hungarian air quality index – was developed jointly by the European Commission’s Directorate General for Environment and the European Environment Agency to inform citizens and public authorities about the recent air quality status across Europe.