IMGW-PIB data - how to download and use it in water monitoring

Knowledge base · July 9, 2026

Many of your own measurements only make sense in the context of weather and hydrology - and in Poland this data is publicly available, free of charge, thanks to IMGW-PIB (the Institute of Meteorology and Water Management - National Research Institute). It is worth knowing what you will find there and how to use it.

What IMGW-PIB provides

• Meteorological data - including air temperature, rainfall, wind, pressure, humidity.
• Hydrological data - including water levels and flows at gauging stations.
• Warnings and information on the hydrological-meteorological situation.

How to download it - a worked example

The Polish service IMGW-PIB is used here as a case study: the pattern repeats across most national hydrometeorological services, so it is worth learning the mechanism rather than a list of addresses. Everything starts at danepubliczne.imgw.pl, which has two parts - a file archive and an API serving current data.

Two parameters cover most needs: one station instead of all - …/api/data/hydro/id/152210040 (you append /id/<code>), and a different format - …/api/data/synop/format/csv (JSON by default; html and xml also exist).

The response is flat JSON - one object per station, no nesting. A fragment of a real response for the Vistula gauge at Warsaw-Nadwilanówka:

{
  "id_stacji": "152210040",
  "stacja": "Warszawa - Nadwilanówka",
  "rzeka": "Wisła",
  "stan_alarmowy": "800",
  "stan_ostrzegawczy": "750",
  "stan_wody": "44",
  "stan_wody_data_pomiaru": "2026-08-12 16:50:00",
  "temperatura_wody": null,
  "przeplyw": "181",
  "przeplyw_data": "2026-08-12 16:50:00"
}

Three things that are easy to trip over - and that you will meet in most public APIs:

1. Values arrive as text, not numbers ("stan_wody": "44") - cast them before any arithmetic.
2. null is normal. Water temperature is often empty when a sensor is down - that is a missing measurement, not a failed download. Skip such records; never replace them with zero.
3. Each field has its own timestamp (stan_wody_data_pomiaru, przeplyw_data) - one record can carry measurements taken at different hours.

A bonus for monitoring: the hydrological record contains the warning and alarm levels for the gauge - ready-made thresholds to compare your own readings against.

Archival data

The live API returns only the latest measurement. Historical series (daily and monthly, decades back) are in the file archive: danepubliczne.imgw.pl/datastore - directories of CSV/ZIP files for meteorological and hydrological data.

Terms of use

The data are free of charge, but the terms require attribution: publications based on them must state that the data come from IMGW-PIB, and if the data were processed - add a note about the processing. Full text: terms of provision. Check the equivalent rule for your own national service - free almost never means “no conditions”.

What to use it for

IMGW data is ready-made context for your measurements:

• rainfall explains changes in water level and turbidity (run-off after rain),
• temperature helps you understand fluctuations in oxygen, the risk of cyanobacterial blooms, and even bark-beetle swarming,
• levels and flows upstream help interpret what is happening at your point.

In practice

📊 See a working example: Vistula - Warsaw (Nadwilanówka) - a public dashboard fed by exactly this API, the address …/api/data/hydro/id/152210040 from the example above. Water level and discharge pulled automatically every hour, with no login and no manual stitching of files. (Source of the data: Institute of Meteorology and Water Management - National Research Institute.)

You can connect your own gauge in the same way: in LimnoLog connectors query public APIs at a chosen rhythm and save the results next to your own measurements, on a shared timeline. More on combining data in How to combine your own measurements with public data.