Sweden Historical River Discharge Dataset

What this looks like

One real series from the dataset, and real rows from the head of its published extract. Neither is a mock-up: the rows below are the same rows, unchanged, that are in the file you would download.

Mean river flow at ÖVRE HYNDEVAD

The longest single series this dataset holds — 50,310 daily values, one of 694. Drawn from 600 of them, evenly spaced across the record. The dataset is not this chart.

Drawn to show the shape and resolution of what the dataset contains, not to make a point about ÖVRE HYNDEVAD. Gaps are breaks, never interpolated.

View the data behind this chart

Underlying data
Period	ÖVRE HYNDEVAD (m³/s)
1889	27.0
1890	17.0
1891	20.0
1892	21.0
1893	12.0
1894	22.0
1895	47.0
1896	18.0
1897	30.0
1898	38.0
1899	70.0
1900	11.0
1901	20.0
1902	7.90
1903	15.0
1904	38.0
1905	9.80
1906	21.0
1907	14.0
1908	18.0
1909	11.0
1910	89.0
1911	48.0
1912	22.0
1913	54.0
1914	19.0
1915	10.0
1916	21.0
1917	41.0
1918	20.0
1919	22.0
1920	4.40
1921	10.0
1922	3.00
1923	3.70
1924	57.0
1925	24.0
1926	4.10
1927	22.0
1928	6.50
1929	22.0
1930	25.0
1931	26.0
1932	10.0
1933	6.90
1934	3.00
1935	71.0
1936	26.0
1937	8.50
1938	20.0
1939	102
1940	14.3
1941	17.0
1942	8.80
1943	16.3
1944	20.0
1945	80.0
1946	10.3
1947	22.0
1948	3.30
1949	7.20
1950	69.0
1951	37.0
1952	41.0
1953	34.0
1954	20.0
1955	67.0
1956	32.0
1957	24.0
1958	25.0
1959	52.0
1960	22.0
1961	58.0
1962	31.0
1963	22.0
1964	21.0
1965	27.0
1966	25.0
1967	82.0
1968	23.0
1969	30.0
1970	8.80
1971	28.0
1972	26.0
1973	29.0
1974	10.6
1975	74.0
1976	7.00
1977	22.0
1978	27.0
1979	12.2
1980	27.0
1981	33.0
1982	62.0
1983	43.0
1984	37.0
1985	30.0
1986	48.0
1987	26.0
1988	79.0
1989	42.0
1990	53.0
1991	26.0
1992	12.6
1993	22.0
1994	48.0
1995	18.4
1996	4.30
1997	24.5
1998	33.4
1999	32.7
2000	27.6
2001	64.8
2002	53.0
2003	3.10
2004	27.0
2005	23.1
2006	20.2
2007	58.0
2008	64.5
2009	38.0
2010	53.0
2011	31.5
2012	38.0
2013	38.0
2014	38.5
2015	22.0
2016	29.7
2017	3.30
2018	42.7
2019	10.0
2020	46.0
2021	16.0
2022	6.60
2023	59.1
2024	90.0
2025	65.7
2026	60.0

Sample rows

12 of 9,563,204 rows Taken from the start of observations-river-flow-se-smhi-hydro.csv. These are sample rows, not the dataset.

Sample rows from the Sweden Historical River Discharge Dataset extract
`metric_id`	`subject_id`	`subject_kind`	`value`	`censored`	`censor_operator`	`censor_threshold`	`censor_limit`	`censor_reported`	`unit`	`period_start`	`period_end`	`period_kind`	`basis`	`confidence`	`source_id`	`source_ref`	`qualifier`	`superseded`	`retrieved`
river-flow-mean	se-smhi-10	geography	6	—	—	—	—	—	m³/s	1917-01-01	1917-01-01	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.9	—	—	—	—	—	m³/s	1917-01-02	1917-01-02	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.9	—	—	—	—	—	m³/s	1917-01-03	1917-01-03	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.8	—	—	—	—	—	m³/s	1917-01-04	1917-01-04	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.7	—	—	—	—	—	m³/s	1917-01-05	1917-01-05	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.7	—	—	—	—	—	m³/s	1917-01-06	1917-01-06	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.6	—	—	—	—	—	m³/s	1917-01-07	1917-01-07	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.5	—	—	—	—	—	m³/s	1917-01-08	1917-01-08	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.5	—	—	—	—	—	m³/s	1917-01-09	1917-01-09	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.4	—	—	—	—	—	m³/s	1917-01-10	1917-01-10	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.4	—	—	—	—	—	m³/s	1917-01-11	1917-01-11	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01
river-flow-mean	se-smhi-10	geography	5.3	—	—	—	—	—	m³/s	1917-01-12	1917-01-12	day	measured	high	se-smhi-hydro	10	—	—	2026-10-01

Download these rows as CSV — the same twelve, with the column header, for testing a loader before committing to the full file.

Methodology

Collected 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.

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)

Attribution and citation

Cite and reuse →

Two different obligations, deliberately kept apart. One is a condition of somebody else's licence; the other is a request Hydrionis has no standing to enforce.

Attribution you are required to give

These are conditions of the licences the underlying data is published under. They are obligations to the publishers, not to Hydrionis, and they apply to you directly whether or not you mention Hydrionis at all.

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

Sveriges meteorologiska och hydrologiska institut — CC BY 4.0 (licence text)

Suggested citation for Hydrionis

Hydrionis (2026), Sweden Historical River Discharge Dataset, version 1.0.0, accessed 2026-10-05, hydrionis.com/data/datasets/sweden-river-discharge/

Cite Hydrionis where you rely on the compilation, the normalisation, the eligibility judgements or a chart. Where you use an unmodified published value, the publisher’s attribution is the one that is required; crediting Hydrionis as well is welcome and is not something Hydrionis can require of you.

Recommended, not required. Hydrionis does not claim rights over unmodified public data it relayed, and doing arithmetic on somebody else’s measurements does not make them Hydrionis’s. Cite the version and the access date: Sweden Historical River Discharge Dataset changes as publishers release and as methods are revised, and a citation without both cannot be checked later. Full guidance is on cite and reuse.

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.

Use this data

Every bulk extract ships with a companion metadata file carrying this dataset’s version, its sources, their licences, the attribution you are required to give and the suggested citation — so the terms travel with the file rather than staying on this page.

About this data

The fields a professional user needs to judge whether this is fit for a particular purpose. Deliberately not a score.

About this data

Everything below is a property of the data rather than a rating of it. There is deliberately no single confidence score: how much a gap matters depends on what you are about to do with the series, and only you know that.

Source	Sveriges meteorologiska och hydrologiska institut — Swedish hydrological observations · CC BY 4.0
How the values came to exist	Mixed across the series — the basis is recorded on every individual value.
Period held	1851–2026
Known gaps	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.
Continuity	Version 1.0.0, released 2026-08-25. 1 recorded version; breaking changes and corrections are listed in the changelog above.
Last read from the publisher	2026-10-01 · publisher updates daily
Redistribution	Permitted by the upstream licences
Commercial reuse	Permitted by the upstream licences. No Hydrionis access tier can widen this.
Methodology	How this was produced