Sweden Historical River Discharge Dataset

Methodology

Ingested from the SMHI open data hydrological service under CC BY 4.0. Values are stored as SMHI publishes them and are not recomputed: SMHI derives each daily discharge from its own sub-daily measurement and rating curves, and a mean recalculated by Hydrionis from whatever sub-daily data happened to be exposed would be a different statistic under the same name. SMHI marks every value checked-and-approved, roughly-checked or unchecked, and all three levels are stored — the roughly-checked periods sit inside continuous records rather than at their ends, so excluding them would leave silent gaps. Each series states which of its periods carry which level, and takes the weakest as its confidence. Values carrying an unrecognised quality code, or an empty cell, are refused rather than converted.

What this dataset cannot tell you

Read before relying on these figures

Discharge is a property of a gauging station and its reach, not of a river. Two stations on the same watercourse routinely differ by an order of magnitude, and no figure here describes a river as a whole.
Quality is not uniform across a record. About 96% of values are checked and approved by SMHI; the rest are roughly checked or not yet checked, and they are not confined to recent data — one station carries an unchecked year in 1923. Each series names its own periods rather than leaving a reader to assume.
A great many Swedish rivers are regulated for hydropower. Discharge at a regulated station reflects operating decisions as much as hydrology, and a change in the record may be a change in operation rather than in rainfall or runoff. SMHI does not publish a regulation flag through this service, so Hydrionis cannot mark which stations are affected.
Rating curves are revised over a century-long record, and a revision changes the discharge computed from the same water level. SMHI republishes corrected values rather than annotating breaks, so a long series is not guaranteed to be homogeneous even where it is continuous.
Twenty-four stations in the network publish no corrected archive at all and are absent, and two returned a header with no values. Both are closed or very short-lived gauges.

Coverage

Subjects	Swedish hydrological gauging stations with a corrected archive — 694 held
Period	1851–2026
Units	m³/s
Update cadence	Daily
Identifier	`sweden-river-discharge` v1.0.0

Fields

Data dictionary →

Every metric this dataset carries, with the unit it is stored in and the geography level it is reported at. Full definitions are in the data dictionary.

Identifier	Field	Unit	Reported at
`river-flow-mean`	Mean river flow Average volumetric discharge past a gauging station over a stated period.	m³/s	river-gauge

Rights and access

Licence position

Open with attribution. Derivative use true; redistribution true; commercial reuse true.

Attribution required:

Data from Sveriges meteorologiska och hydrologiska institut, used under CC BY 4.0.

Permitted uses

Public display
Derived analysis
API delivery
Bulk download
Commercial use

Available to: Public, Developer, Research, Professional, Enterprise. These follow from the rights of the contributing publishers, not from a Hydrionis pricing decision — no access tier can widen what a publisher withheld.

Contributing sources

Sveriges meteorologiska och hydrologiska institut — Swedish hydrological observations (CC BY 4.0)

Suggested citation

Hydrionis (2026), Sweden Historical River Discharge Dataset, version 1.0.0. Retrieved from https://hydrionis.com/data/datasets/sweden-river-discharge/

Cite the version. Hydrionis datasets change as publishers release and as methods are revised, and a citation without a version cannot be checked later.

Changelog

Version 1.0.0 — 2026-08-25

First release. Sweden becomes the deepest river record on the platform.

Additions

Daily discharge for 694 stations across 87 main drainage basins, 1851 onward.
Catchment name, official basin number and basin area carried onto every station.

Getting the data

Machine-readable metadata for this dataset is at /api/v1/datasets/sweden-river-discharge.json. For bulk extracts, higher-volume access or commercial licensing, see data enquiries.