Chemical composition of precipitation (concentrations of individual compounds) – verified primary data and aggregated data

In accordance with Annex 2 of Decree No. 106/2025 Coll., implementing certain provisions of the Act on the Public Hydrometeorological Service, CHMI has made available verified and aggregated data for concentrations of precipitation chemical composition. These include precipitation amount (RAIN), conductivity (cond), pH, arsenic (As), calcium ions (Ca²⁺), cadmium (Cd), chloride ions (Cl⁻), cobalt (Co), chromium (Cr), copper (Cu), fluoride ions (F⁻), iron (Fe), mercury (Hg), potassium ions (K⁺), magnesium ions (Mg²⁺), manganese (Mn), sodium ions (Na⁺), ammonium ions (NH₄⁺), nickel (Ni), nitrate ions (NO₃⁻), lead (Pb), total phosphorus (P-sum), selenium (Se), sulfate ions (SO₄²⁻), strontium (Sr), vanadium (V), zinc (Zn), and selected persistent organic pollutants: polycyclic aromatic hydrocarbons (POPs-PAH) and polychlorinated biphenyls (POPs-PCB).

The data are available from 1976 onwards and are site-specific. Primary data are provided in sampling intervals of 1 day, 1 week, 1 month, or irregularly, depending on the type of measurement. Aggregated data are calculated from the above-mentioned primary data. These include weekly, monthly, and annual concentrations, as well as weekly, monthly, and annual deposition.

The most recent verified data are approximately 18 months old relative to the current date, reflecting the data verification process.