The monitoring network within this area

Hydrionis holds 118,836 values from 13 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.

13
Gauges
118,836
Values held
1931–2026
Record spans
Gauges within the Ähtävänjoki drainage basin
13 monitoring points, positioned as the publisher records them.
Gauges within the Ähtävänjoki drainage basinKurejoki, Lappajärvi - luusua, Evijärvi - luusua, Ähtävänjoki, Hanhikoski, Björkfors, Kattilakoski, Herrfors, Hattar, Evijärvi, Kaarenhaara, Björkfors, Q, Långfors, Värnum, FinnholmKurejokiLappajärvi - luusuaEvijärvi - luusuaÄhtävänjoki, HanhikoskiBjörkforsKattilakoskiHerrforsHattarEvijärvi, KaarenhaaraBjörkfors, QLångforsVärnumFinnholm

The longest record here

Mean river flow at Herrfors
Annual means of the daily record, 1965–2025. One gauge, not this drainage area.
Mean river flow at HerrforsMean river flow at Herrfors: Herrfors in m³/s, from 1965 to 2025.510152025m³/s19651976198419922000200820162024Herrfors 1965: 12.9 m³/sHerrfors 1966: 12.7 m³/sHerrfors 1969: 10.7 m³/sHerrfors 1970: 9.73 m³/sHerrfors 1972: 17.2 m³/sHerrfors 1973: 12.5 m³/sHerrfors 1974: 17.3 m³/sHerrfors 1975: 15.5 m³/sHerrfors 1976: 8.63 m³/sHerrfors 1977: 15.4 m³/sHerrfors 1978: 8.47 m³/sHerrfors 1979: 10.9 m³/sHerrfors 1980: 12.6 m³/sHerrfors 1981: 24.6 m³/sHerrfors 1982: 23.4 m³/sHerrfors 1983: 18.1 m³/sHerrfors 1984: 16.6 m³/sHerrfors 1985: 11.8 m³/sHerrfors 1986: 14.2 m³/sHerrfors 1987: 22.5 m³/sHerrfors 1988: 18.2 m³/sHerrfors 1989: 16.5 m³/sHerrfors 1990: 13.5 m³/sHerrfors 1991: 11.6 m³/sHerrfors 1992: 16.6 m³/sHerrfors 1993: 16.4 m³/sHerrfors 1994: 13.3 m³/sHerrfors 1995: 14.9 m³/sHerrfors 1996: 9.08 m³/sHerrfors 1997: 13.9 m³/sHerrfors 1998: 18.8 m³/sHerrfors 1999: 12.7 m³/sHerrfors 2000: 17.1 m³/sHerrfors 2001: 18.2 m³/sHerrfors 2002: 10.8 m³/sHerrfors 2003: 9.45 m³/sHerrfors 2004: 15.7 m³/sHerrfors 2005: 13.9 m³/sHerrfors 2006: 12.1 m³/sHerrfors 2007: 14.2 m³/sHerrfors 2008: 19.7 m³/sHerrfors 2009: 11.9 m³/sHerrfors 2010: 14.2 m³/sHerrfors 2011: 19.6 m³/sHerrfors 2012: 24.5 m³/sHerrfors 2013: 16.8 m³/sHerrfors 2014: 13.4 m³/sHerrfors 2015: 23.6 m³/sHerrfors 2016: 21.3 m³/sHerrfors 2017: 15.8 m³/sHerrfors 2018: 11.9 m³/sHerrfors 2019: 11.7 m³/sHerrfors 2020: 20.1 m³/sHerrfors 2021: 18.2 m³/sHerrfors 2022: 16.5 m³/sHerrfors 2023: 23.6 m³/sHerrfors 2024: 18.4 m³/sHerrfors 2025: 12.7 m³/s

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
PeriodHerrfors (m³/s)
196512.9
196612.7
196910.7
19709.73
197217.2
197312.5
197417.3
197515.5
19768.63
197715.4
19788.47
197910.9
198012.6
198124.6
198223.4
198318.1
198416.6
198511.8
198614.2
198722.5
198818.2
198916.5
199013.5
199111.6
199216.6
199316.4
199413.3
199514.9
19969.08
199713.9
199818.8
199912.7
200017.1
200118.2
200210.8
20039.45
200415.7
200513.9
200612.1
200714.2
200819.7
200911.9
201014.2
201119.6
201224.5
201316.8
201413.4
201523.6
201621.3
201715.8
201811.9
201911.7
202020.1
202118.2
202216.5
202323.6
202418.4
202512.7

Every gauge Hydrionis holds within this area

Gauges within the Ähtävänjoki and what each holds
GaugeMeasuresValuesRecord
Herrforsmean river flow21,9141965–2026
Ähtävänjoki, Hanhikoskimean river flow20,3091971–2026
Kurejokimean river flow16,2861982–2026
Kattilakoskimean river flow16,2001982–2026
Björkforsmean river flow10,6531967–1998
Lappajärvi - luusuamean river flow10,5901931–1964
Evijärvi - luusuamean river flow8,0351933–1954
Hattarmean river flow4,4542014–2026
Evijärvi, Kaarenhaaramean river flow3,7552016–2026
Björkfors, Qmean river flow1,9942021–2026
Finnholmmean river flow1,9942021–2026
Långforsmean river flow1,9932021–2026
Värnummean river flow6592024–2026

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 — 47. 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
GaugeEvidenceEstablished
HerrforsStated by the publisher on the record this gauge’s observations came from.With the observations
Ähtävänjoki, HanhikoskiStated by the publisher on the record this gauge’s observations came from.With the observations
KurejokiStated by the publisher on the record this gauge’s observations came from.With the observations
KattilakoskiStated by the publisher on the record this gauge’s observations came from.With the observations
BjörkforsStated by the publisher on the record this gauge’s observations came from.With the observations
Lappajärvi - luusuaStated by the publisher on the record this gauge’s observations came from.With the observations
Evijärvi - luusuaStated by the publisher on the record this gauge’s observations came from.With the observations
HattarStated by the publisher on the record this gauge’s observations came from.With the observations
Evijärvi, KaarenhaaraStated by the publisher on the record this gauge’s observations came from.With the observations
Björkfors, QStated by the publisher on the record this gauge’s observations came from.With the observations
FinnholmStated by the publisher on the record this gauge’s observations came from.With the observations
LångforsStated by the publisher on the record this gauge’s observations came from.With the observations
VärnumStated 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
SignalHeldCounts
Gauges holding a real record13yes, 3 or more
Years spanned96yes, 20 or more
Values held118,836yes, 1000 or more
Distinct measurements1no
Publishers measuring it1no
Official identifiers1recorded, not counted

Where these figures come from

MeasuredHigh confidence2026-08-25

Source: SykeHydrologiarajapinta — Finnish national hydrological archive, 4700650. Licence: Open — attribution required (attribution required).

Method: Daily discharge exactly as the Finnish Environment Institute publishes it. Syke computes the daily value from its own 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. Values Syke flags as possibly erroneous are not stored.

2 of these values (under 1%) are interpolated by Syke rather than measured, and are marked as such in its own archive. Station in the Ähtävänjoki main drainage basin, Herrforsin a sub-basin. Discharge is a property of this gauge and this reach, not of the river as a whole.

Retrieved 26 August 2026.