In accordance with Annex 2 of Decree 106/2025, which implements certain provisions of the Act on the Public Hydrometeorological Service, the Czech Hydrometeorological Institute (CHMI) provides current operational (unverified) hourly data on outdoor air pollutants (pollutant concentrations from monitoring stations with automated measurement programs, as specified by Act No. 201/2012 Coll., on Air Protection).
The data made available include key pollutants with ambient air quality limits under current legislation: nitrogen dioxide (NO₂), nitrogen oxides (NOₓ), ground-level ozone (O₃), suspended particles PM₁₀ and PM₂.₅, sulfur dioxide (SO₂), and carbon monoxide (CO).
The data are based on measurements taken at stations owned by CHMI.
In accordance with Annex 2 of Decree 106/2025 Coll., which implements certain provisions of the Act on the Public Hydrometeorological Service, the Czech Hydrometeorological Institute (CHMI) has made operational (unverified) primary and aggregated data available for outdoor air pollutants (pollutant concentrations from automatic monitoring stations, provided in the scope and temporal aggregations specified by Act No. 201/2012 Coll., on Air Protection).
The data include key pollutants with ambient air limit values under current legislation: arsenic (As), benzene, benzo[a]pyrene, cadmium (Cd), carbon monoxide (CO), nickel (Ni), nitrogen dioxide (NO₂), nitrogen oxides (NOₓ), ground-level ozone (O₃), lead (Pb), suspended particles PM₁₀, suspended particles PM₂.₅, and sulfur dioxide (SO₂).
The data are based on measurements from CHMI-owned stations since 1969. Primary data are provided in measurement intervals of 30 minutes, 1 hour, or 24 hours, depending on the type of measurement. Aggregated data are calculated from the aforementioned primary data and include the following: daily averages, monthly averages, annual averages, and the number of exceedances of ambient air limit values. Preliminary data include air quality information that is older than one hour. Verified data can be found in the dataset *Air Quality Measurements – Verified Data*, in accordance with the data verification process. Verification is carried out once a year, no later than July 1st (YYYY-1).
In accordance with Annex 2 of Decree 106/2025 Coll., which implements certain provisions of the Act on the Public Hydrometeorological Service, the Czech Hydrometeorological Institute (CHMI) has made verified primary and aggregated data available for outdoor air pollutants (pollutant concentrations from Concentration of pollutants from monitoring stations with automatic and manual programs, provided in the scope and temporal aggregations specified by Act No. 201/2012 Coll., on Air Protection).
The data include key pollutants with ambient air limit values under current legislation: arsenic (As), benzene, benzo[a]pyrene, cadmium (Cd), carbon monoxide (CO), nickel (Ni), nitrogen dioxide (NO₂), nitrogen oxides (NOx), ground-level ozone (O₃), lead (Pb), suspended particles PM10, suspended particles PM2.5, and sulfur dioxide (SO₂).
The data are based on measurements from CHMI-owned stations since 1969. Primary data are provided in measurement intervals of 30 minutes, 1 hour, or 24 hours, depending on the type of measurement. Aggregated data are calculated from the aforementioned primary data and include the following: daily averages, monthly averages, annual averages, and the number of exceedances of ambient air limit values.
The most recent verified data available date back approximately 18 months from the current date, in accordance with the data verification process.
In accordance with Annex 2 of Decree 106/2025 Coll., which implements certain provisions of the Act on the Public Hydrometeorological Service, the Czech Hydrometeorological Institute (CHMI) provides yearbooks. The Yearbook “Air Pollution in the Czech Republic in the YYYY,” together with the published data yearbook “Summary Tabular Overview” and the methodological material “Data Collection, Processing, and Evaluation System,” provides a complete overview of air quality information in the Czech Republic for the given year. The air quality assessment is based on measured data collected within the ISKO framework, utilizing additional resources and mathematical tools. The data yearbook presents verified measured concentration data and information on the chemical composition of atmospheric precipitation from various locations, including aggregated data. The graphical yearbook offers summarized information with commentary in the form of detailed maps, graphs, and tables.
In accordance with Annex 2 of Decree 106/2025 Coll., which implements certain provisions of the Act on the Public Hydrometeorological Service, the Czech Hydrometeorological Institute (CHMI) provides data (tabular) yearbooks. The summary annual tabular survey “Air Pollution and Atmospheric Deposition in Data, the Czech Republic...” (hereinafter referred to as the Tabular Survey) is published as a basic overview of measured pollutant concentrations in ambient air in the Czech Republic for the given calendar year. It is primarily intended for use by state administration authorities and organizations dealing with environmental issues and air quality protection in the Czech Republic.
According to Regulation 2018/1999 of the European Parliament and of the Council of the EU, all EU Member States are required to report their approximate (proxy) GHG emission inventories for year (t-1) by 31 July of the current year (t). These are only approximate estimates. Final GHG emission inventories are published the following year (t+1).
Pollutants with air quality limits set for health protection with an averaging period of 1 calendar year:
NO₂_rp_5l: NO₂ – annual average concentration [µg·m⁻³], PM₁₀_rp_5l: PM₁₀ – annual average concentration [µg·m⁻³], PM₂₅_rp_5l: PM₂.₅ – annual average concentration [µg·m⁻³], BZN_rp_5l: benzene – annual average concentration [µg·m⁻³], BaP_rp_5l: benzo[a]pyrene – annual average concentration [ng·m⁻³], As_rp_5l: arsenic – annual average concentration [ng·m⁻³], Pb_rp_5l: lead – annual average concentration [ng·m⁻³], Ni_rp_5l: nickel – annual average concentration [ng·m⁻³], Cd_rp_5l: cadmium – annual average concentration [ng·m⁻³].
Pollutants with air quality limits set for health protection with an averaging period of 24 hours:
PM₁₀h24_5l: PM₁₀ – 36th highest 24-hour average concentration in a calendar year [µg·m⁻³],
SO₂h24_5l: SO₂ – 4th highest 24-hour average concentration in a calendar year [µg·m⁻³].
Pollutants with air quality limits set for the protection of ecosystems and vegetation:
SO₂_rp_5l: SO₂ – annual average concentration [µg·m⁻³],
SO₂_zp_5l: SO₂ – average concentration for the winter period (1.10.–31.3.) [µg·m⁻³],
NOₓ_rp_5l: NOₓ – annual average concentration [µg·m⁻³].
The Czech Republic, like all states that are parties to the United Nations Framework Convention on Climate Change (UNFCCC), is obliged to implement international measures to mitigate climate change caused by anthropogenic activities, within the framework of which it must also regularly publish projections of greenhouse gas emissions. By reporting projections, the Czech Republic also fulfils its obligations as an EU Member State under Article 18 of Regulation 2018/1999. The Czech Hydrometeorological Institute (CHMI) is responsible for the implementation and submission of these reports and reports every two years, on 15 March (t-2), to the European Commission and the UNFCCC Secretariat, which then use them to develop further legislation and policy measures to reduce emissions or increase sinks (removals) of greenhouse gases.
According to Regulation 2018/1999 of the European Parliament and of the Council of the EU, all EU Member States are required to report their National Inventory Report to the European Commission annually by 15 March of the following year (t+1) together with the official reporting tables (CRF – Common Reporting Format); and to the UNFCCC Secretariat by 15 September, which has been implemented since 2024 under the new terms of the Paris Agreement, now in the CRT (Common Reporting Tables) format. Under the Paris Agreement, the Czech Republic, as an EU member state, has agreed to jointly reduce greenhouse gas emissions by at least 40 % by 2030 compared to 1990.
In accordance with Act 123/1998 Coll. on free access to environmental information, as amended, the CHMI has provided verified primary and aggregated data on outdoor air pollutants. These are the main pollutants with limit values according to current legislation: arsenic (As), benzene, benzo[a]pyrene, cadmium (Cd), carbon monoxide (CO), nickel (Ni), nitrogen dioxide (NO2), nitrogen oxides (NOX), ground-level ozone (O3), lead (Pb), particulate matter (PM10), particulate matter (PM2.5), sulphur dioxide (SO2). The data are based on measurements at stations owned by the CHMI for the period 1969-2022. The primary data are presented in measurement intervals of 30 min, 1 h or 24 h, depending on the type of measurement. Aggregated data are calculated from the above primary data. These data are: daily mean values, monthly mean values, annual mean values and the number of exceedances of the limit values for the protection of human health. Verified data for subsequent calendar years from 2020 will always be available by 1 July of the following year.
According to Regulation 2018/1999 of the European Parliament and of the Council of the EU, all EU Member States are required to report their National Inventory Report to the European Commission annually by 15 March of the following year (t+1) together with the official reporting tables (CRF – Common Reporting Format); and to the UNFCCC Secretariat by 15 September, which has been implemented since 2024 under the new terms of the Paris Agreement, now in the CRT (Common Reporting Tables) format. Under the Paris Agreement, the Czech Republic, as an EU member state, has agreed to jointly reduce greenhouse gas emissions by at least 40 % by 2030 compared to 1990.
The Czech Republic, like all states that are parties to the United Nations Framework Convention on Climate Change (UNFCCC), is obliged to implement international measures to mitigate climate change caused by anthropogenic activities, within the framework of which it must also regularly publish projections of greenhouse gas emissions. By reporting projections, the Czech Republic also fulfils its obligations as an EU Member State under Article 18 of Regulation 2018/1999. The Czech Hydrometeorological Institute (CHMI) is responsible for the implementation and submission of these reports and reports every two years, on 15 March (t-2), to the European Commission and the UNFCCC Secretariat, which then use them to develop further legislation and policy measures to reduce emissions or increase sinks (removals) of greenhouse gases.