This dataset presents daily data on O3 concentrations for each Brazilian municipality, from May 11, 2019 to 2024. We used the Copernicus Atmosphere Monitoring Service (CAMS) global reanalysis (EAC4) as a source to compute zonal statistics for the official boundaries of Brazilian municipalities. The following datasets were computed: Minimum values: for each municipality boundary and day, the hourly minimum values of O3 (µg/m³) of all intersecting cells are averaged, resulting in the municipality's minimum daily indicator. Maximum values: for each municipality boundary and day, the hourly maximum values of O3 (µg/m³) of all intersecting cells are averaged, resulting in the municipality's maximum daily indicator. Average values: for each municipality boundary and day, the hourly average values of O3 (µg/m³) of all intersecting cells are averaged, resulting in the municipality's average daily indicator. Those indicators are presented in Parquet and CSV formats. The computational codes used to create those datasets are openly available here. Disclaimer: "Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains."