The monitoring network within this area

Hydrionis holds 47,532 values from 4 gauges within it. Discharge is a property of a gauge and its reach, not of this drainage area, so this page reports the network and its records rather than a single figure.

4

Gauges

47,532

Values held

1925–2026

Record spans

1,176 km²

Area

Gauges within the Tämnarån drainage basin

4 monitoring points, positioned as the publisher records them.

How low, how high and how variable this gauge runs

A hydrograph says what happened; these say how often. Read off TÄRNSJÖ's whole daily record between 1974 and 2026, they describe the shape of the record rather than any day in it — and they belong to this gauge and its reach, not to this drainage area.

0.028 m³/s

Q95 low flow

0.075 m³/s

Q50 median flow

0.213 m³/s

Q10 high flow

Largest day of each water year at TÄRNSJÖ

The highest daily mean discharge in each October-to-September water year, 1974–2025.

These are the largest daily means, not flood peaks. A peak lasting hours is averaged across a whole day here, so the true instantaneous maximum on the same day was higher — sometimes far higher on a fast-responding catchment. Flood frequency work needs a publisher's own instantaneous series; Hydrionis holds one for 2,236 American gauges and not for this one, so the two are never drawn together. A water year the gauge did not substantially cover produces no value at all rather than a low one.

View the data behind this chart

Underlying data
Period	TÄRNSJÖ (m³/s)
1974	0.380
1975	0.200
1976	0.750
1977	0.430
1978	0.690
1979	0.470
1980	0.530
1981	0.600
1982	0.380
1983	0.620
1984	0.810
1985	1.04
1986	0.440
1987	0.570
1988	0.250
1989	0.440
1990	0.240
1991	0.280
1992	0.320
1993	0.340
1994	0.410
1995	0.200
1996	0.520
1997	0.300
1998	0.860
1999	0.330
2000	0.570
2001	0.680
2002	0.370
2003	0.310
2004	0.390
2005	0.740
2006	0.430
2007	0.360
2008	0.620
2009	0.670
2010	0.800
2011	0.340
2012	0.950
2013	0.330
2014	0.380
2015	0.330
2016	0.190
2018	0.450
2019	0.480
2020	0.310
2021	0.450
2023	0.630
2024	0.520
2025	0.390

The longest record here

Mean river flow at TÄRNSJÖ

Annual means of the daily record, 1975–2025. One gauge, not this drainage area.

Annual means computed by Hydrionis from the published daily record, drawn only for years with at least 300 days held. They summarise this gauge's own record and say nothing about any other watercourse in this area.

View the data behind this chart

Underlying data
Period	TÄRNSJÖ (m³/s)
1975	0.091
1976	0.067
1977	0.143
1978	0.097
1979	0.122
1980	0.128
1981	0.169
1982	0.138
1983	0.109
1984	0.138
1985	0.156
1986	0.155
1987	0.121
1988	0.109
1989	0.079
1990	0.093
1991	0.073
1992	0.093
1993	0.079
1994	0.088
1995	0.097
1996	0.077
1997	0.089
1998	0.123
1999	0.124
2000	0.123
2001	0.105
2002	0.123
2003	0.091
2004	0.093
2005	0.090
2006	0.119
2007	0.103
2008	0.125
2009	0.106
2010	0.093
2011	0.091
2012	0.119
2013	0.086
2014	0.102
2015	0.093
2016	0.077
2017	0.076
2018	0.087
2019	0.106
2020	0.081
2021	0.095
2022	0.080
2023	0.128
2024	0.139
2025	0.107

Every gauge Hydrionis holds within this area

Gauges within the Tämnarån and what each holds
Gauge	Measures	Values	Record
TÄRNSJÖ	mean river flow	19,024	1974–2026
NÄS	mean river flow	16,987	1925–1971
ODENSFORS	mean river flow	7,397	1930–1950
NÄS 2 TÄMNARÅN	mean river flow	4,124	2015–2026

How these gauges were attached to this water

Assigned by the publisher to a numbered basin Every gauge here is assigned to this drainage area by its own publisher, which issues the area an official code — 54000. A drainage area is not a river: it contains the tributaries as well as the main channel, and a gauge in it may be on any of them.

What each gauge’s link to this water rests on
Gauge	Evidence	Established
TÄRNSJÖ	Stated by the publisher on the record this gauge’s observations came from.	With the observations
NÄS	Stated by the publisher on the record this gauge’s observations came from.	With the observations
ODENSFORS	Stated by the publisher on the record this gauge’s observations came from.	With the observations
NÄS 2 TÄMNARÅN	Stated by the publisher on the record this gauge’s observations came from.	With the observations

What this record holds

Hydrionis decides which waters get a page, and which of those are offered to search, from what is actually held rather than from how the page reads. Five signals are counted; this record has 3 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	4	yes, 3 or more
Years spanned	102	yes, 20 or more
Values held	47,532	yes, 1000 or more
Distinct measurements	1	no
Publishers measuring it	1	no
Official identifiers	2	recorded, not counted

Use this data

Machine-readable JSON /api/v1/observations/by-subject/se-smhi-2299.json
How to cite this, and who you must credit
How these figures were produced
Request this at a different scale, format or geography

No bulk download is offered here, which is a licence position rather than a product one: at least one contributing publisher does not permit redistribution. The values can be read on the page, cited, and pointed to at source.

Attribution and citation

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), Tämnarån gauge records, accessed 2026-10-05, hydrionis.com/waters/sweden-tamnaran/

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: the Tämnarån gauge records 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.

Where these figures come from

MeasuredMedium confidence2026-09-30

Source: SMHI — Swedish hydrological observations, 2299. Licence: Open — attribution required (attribution required).

Method: Daily discharge exactly as SMHI publishes it, from its corrected archive. SMHI computes the daily value from its own sub-daily measurement and rating curves; Hydrionis does not recompute it, because a mean derived from whatever sub-daily data happens to be exposed would be a different statistic under the same name.

Checked and approved by SMHI except 2026-01-06 to 2026-09-30 (not yet checked). Station in the TÄMNARÅN main drainage basin, 14 km². Discharge is a property of this gauge and this reach, not of the river as a whole.

Retrieved 1 October 2026.