Hydrology

Overview

IMGW publishes hydrological observations for the Polish river-gauge network at daily and monthly resolution, as open data from the public data portal. No authentication is required.

Values are downloaded as zipped CSV archives and decoded as latin-1. The archive layout has changed over time — daily data is split into per-month files (codz_YYYY_MM.zip) historically and consolidated into a single per-year file (codz_YYYY.zip) from 2023 onwards — which wetterdienst normalizes transparently.