Open environmental data - which sources are worth knowing
Before you start measuring on your own, it is worth knowing what is already publicly available - because much environmental data in Poland can be downloaded for free. It is useful as context for your own measurements, as a reference and often as ready-made material for analysis. Here is an overview of the most important sources.
The most important sources
Below, Poland is used as a worked example - the categories (hydrometeorology, environmental inspection, water management, spatial data, statistics, EU-wide services) repeat in every country, so it is the list of categories that transfers, not the individual addresses.
| Source | What you will find | Address | Form |
|---|---|---|---|
| Hydrometeorological service (here: IMGW-PIB) | weather and hydrology: rainfall, water levels, discharge | danepubliczne.imgw.pl · API description | REST/JSON + CSV files |
| Environmental inspection - air (here: GIOŚ) | stations, hourly measurements, air-quality index | powietrze.gios.gov.pl · swagger | REST/JSON |
| Environmental inspection - water | status assessments of water bodies, monitoring results | wody.gios.gov.pl | periodic reports and datasets |
| Water management authority (here: Wody Polskie) | river-basin management plans, water-body codes and maps, permits | wody.gov.pl | documents, GIS layers |
| National geoportal | hydrography, orthophotos, boundaries, elevation models | geoportal.gov.pl | WMS/WFS, downloads |
| Sanitary inspection | bathing-water quality during the season | sk.gis.gov.pl | bathing-water service |
| Statistical office | statistics on water management and the environment | bdl.stat.gov.pl | API + exports |
| National open-data portal | aggregates datasets from ministries | dane.gov.pl | datasets + API |
| Copernicus | Earth observation, climate, satellites | copernicus.eu · CDS | API, raster products |
| EEA / WISE | indicators and data on Europe’s waters | water.europa.eu | datasets, dashboards |
(Addresses checked on 12 August 2026.)
⚠️ API addresses do get retired - and that is not a theory. The old version of the Polish
air-quality REST API (api.gios.gov.pl/pjp-api/rest/…) today returns HTTP 410 Gone. If you are
building anything more durable than a one-off download on somebody else’s API, check the response
code and treat 404/410 as a signal to update, not as a temporary outage.
How to use them wisely
- Check the metadata - units, frequency, station location and the method of measurement; without this it is easy to misinterpret.
- Match in time and space - the nearest station and the same time interval are the basis of comparisons.
- Cite the source - in reports and publications.
📊 See it live: Global Rivers & Lakes Watch - a public dashboard from three stations in three countries: the Maumee River (Ohio, USA), the river Main in Frankfurt and the LéXPLORE research platform on Lake Geneva. Water temperature, dissolved oxygen, pH, conductivity, turbidity and chlorophyll-a are fetched automatically (USGS Water Services, WSV Pegelonline, Eawag Datalakes), with correlation tiles and a station map. No login.
In practice
The greatest value comes from setting public data against your own measurements - then you can see the causes and relationships. How to do this without the tedious stitching of spreadsheets, we describe in the article How to combine your own measurements with public data; LimnoLog can pull in some of these sources (IMGW, GIOŚ) automatically through connectors.
See it in the LimnoLog app
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