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River

Kymi River

204 km from source to mouth · Finland.

FinlandFinlandFlows into Gulf of Finland5th longest in Finland

Follow the riverMonth by month

SourceMouth
The river and every tributary in its basin, drawn from RiverATLAS (CC BY 4.0).

In numbers

Length

204km

Average flow

300m³/s

Basin

37,200km²

Drop

61m

from 65 m to 4 m

Country

1

The journey

From source to mouth

204 km of river and 28 stops on the way: 7 towns and cities on its banks, dams, bridges and the tributaries that feed it.

65 m4 m
Päijänneat 65 m0 km
Päijänne1,270 km²49 km
Paljärvi0.7 km²60 km
Ruotsalainen127 km²94 km
Arrajärvi12 km²100 km
Pyhäjärvi62 km²134 km
Kouvola78,824 people153 km
Muhjärvi2.7 km²180 km
Gulf of Finlandat 4 m204 km
050100150204 km
  1. 0 kmPäijänneat 65 m
  2. 49 kmPäijänne1,270 km²
  3. 53 kmKalkkinen600 people
  4. 60 kmPaljärvi0.7 km²
  5. 77 kmHeinola17,746 people
  6. 94 kmRuotsalainen127 km²
  7. 100 kmArrajärvi12 km²
  8. 100 kmKylliäisjärvi0.5 km²
  9. 104 kmKotojärvi1.1 km²
  10. 108 kmHiisiöistenlammi1.8 km²
  11. 109 kmVähä Valkjärvi1.5 km²
  12. 110 kmMärkjärvi4.1 km²
  13. 110 kmTervaslammi0.3 km²
  14. 111 kmValkjärvi3.1 km²
  15. 111 kmIso Pikijärvi0.6 km²
  16. 134 kmPyhäjärvi62 km²
  17. 136 kmSompanen1.5 km²
  18. 145 kmKuusaanlampi1.7 km²
  19. 151 kmKoria5,100 people
  20. 151 kmPioneeripuisto
  21. 151 kmKoria Railway Bridge
  22. 151 kmKoria old railway bridge
  23. 153 kmKouvola78,824 people
  24. 173 kmInkeroinen5,250 people
  25. 174 kmAnjala16,779 people
  26. 179 kmHuruksela
  27. 180 kmMuhjärvi2.7 km²
  28. 201 kmKarhula22,867 people
  29. 202 kmKyminlinna
  30. 204 kmGulf of Finlandat 4 m

Water level along the river (RiverATLAS; the height is exaggerated). Towns: GeoNames and Wikidata; bridges, dams and tributaries: Wikidata.

River in Finland

At the mouth it carries 295 m³/s on average: an Olympic pool every 8.5 seconds. It drops from 65 m to 4 m, 0.3 m per kilometre on average. Its basin covers 37,200 km², about the size of GW. 449,000 people live in it. Highest water, with the snowmelt: from April to May; lowest: from December to March. No large dam holds it back: it is one of the world's free-flowing rivers.

Read more on Wikipedia

Where to start

  • KouvolaLargest city on its banks · 78,824 people
  • Lappeenranta Airport (LPP)Nearest airport with scheduled flights, 80 km from the cityCar hire at LPP airport (Lappeenranta)Discover Cars · Affiliate link
  • On the water50 ferry piers, marinas, boat rentals and boat ramps along the river (OpenStreetMap)
  • Kayak and canoe52 put-ins and rapids mapped (OpenStreetMap)
  • From June to AugustThe best months to visit

Kymi River, month by month

Highest water: from April to May

Lowest water: from December to March. Freezing months (average below −4 °C): from December to February. Melting snow makes up much of its water. Best months to visit: from June to August.

200
-8°40 mmJan
200
-8°31 mmFeb
200
-3°34 mmMar
250
3°36 mmApr
250
10°38 mmMay
240
15°49 mmJun
210
17°69 mmJul
220
15°81 mmAug
220
10°68 mmSep
220
5°65 mmOct
220
-1°64 mmNov
210
-5°53 mmDec
Water (estimated flow)Air (average) Rain (mm)Best months

From about 200 m³/s in the lowest month to 250 m³/s in the highest. An estimate: the monthly flow is modelled from the lowest and highest months of WaterGAP (RiverATLAS, 1971–2000) and the rain and snow along the river (WorldClim). Dams change the real rhythm. The chip is the average air temperature; below it, the month's rain.

Plan the trip

Plan the trip: boat trips, a bed by the river, a car

Some links above are affiliate links: if you book through them we may earn a commission, at no extra cost to you. It never changes what the data on this page says.

The basin

Kymi River: the basin in numbers

26,795 km² of land send their water to this river. This is what lives on it.

Free-flowingDams upstream can hold only 0.0% of a year's flow: the river still keeps its natural rhythm.
  • 449,000people live in the basin
  • 19/km²people per km²
  • 118maverage altitude of the basin
  • 619mmof rain a year (basin average)
  • 3.0°Caverage air temperature
  • 1%protected areas
  • 18.0%covered by lakes

What covers the basin

  • 77% Forest
  • 6% Cropland
  • 1% Towns and cities

RiverATLAS (HydroATLAS v1.0, CC BY 4.0): land cover, people, protected areas, glaciers and dams over the whole basin upstream of the mouth.

Along the river

Kymi River: what you find on the way

  • 15DamsKeltin voimalaitos, Koivukosken powerplant dam, Koivukosken pato and 12 more
  • 11WeirsMyllypuron mittauspato, Siikakoski, Koivukosken pato and 8 more
  • 1Waterfalls
  • 7RapidsKaurakoski, Hirvenjoki, Kultaankoski and 4 more
  • 45Canoe put-insVasikkasaaren rantautumispaikka, Savion rantautumispaikka, Tapolan rantautumispaikka and 42 more
  • 33Boat rampsHevossaaren veneluiska, Sinilähteen veneluiska, Keskustan veneluiska and 30 more
  • 1Ferry piersKalkkinen
  • 15MarinasKalkkisten Vierasvenesatama, Laivaranta, Heinolan satama and 12 more
  • 1Boat rentalsSupventures
  • 22River beachesNaumin uimaranta, Hevossaaren uimaranta, Kaivannon uimaranta and 19 more

From OpenStreetMap, within 2.1 km of the river. Not mapped is not the same as not there.

Cross-checked with our atlases

Kymi River in our other atlases

What our sister atlases know about the waterfalls on this river, the lakes it flows through, the beaches at its mouth, the mountains where it rises and the islands off its mouth.

  • 16lakes on its wayLakeyas
  • 132beaches at the mouth and on the banksCoastya
  • 15islands off the mouthIslandyas

Lakes and reservoirs (16)

Lakes it flows through, by Lakeyas

  1. Päijännekm 52 · 95 m deep1,270km²
  2. Ruotsalainenkm 100127km²
  3. Arrajärvikm 10612km²
  4. Märkjärvikm 1174.1km²
  5. Valkjärvikm 1183.1km²
  6. Pyhäjärvikm 14262km²
  7. Kuusaanlampikm 1551.7km²
  8. Muhjärvikm 1922.7km²

8 more on LakeyasLakeyas is coming soonOpen Lakeyas ↗

Beaches (132)

At the mouth (25 km) and on the banks, by Coastya

  1. Pakustranden22 km away17.3°C
  2. Huutjärvi simstrand9.5 km away17.3°C
  3. Varvet22 km away17.3°C
  4. Sastavi16 km away17.4°C
  5. Pitkäthiekat19 km away17.5°C
  6. Flakanäs badstrand22 km away17.3°C
  7. Kotoranta22 km away · cove17.3°C
  8. Huumanpohjakm 216 · cove17.4°C

124 more on CoastyaOpen Coastya ↗

Islands off the mouth (15)

Within 30 km of the mouth, by Islandyas

  1. Kaunissaari18 km away4.1km²
  2. Kotkansaari4.2 km away
  3. Kukouri7.0 km away
  4. Varissaari6.2 km away
  5. Rankki14 km away
  6. Kuusinen5.0 km away
  7. Kuutsalo9.1 km away
  8. Mussalo5.6 km away

7 more on IslandyasIslandyas is coming soonOpen Islandyas ↗

From space

The source and the mouth, seen from orbit

Kymi River: satellite view of the source
The source14 km across
Kymi River: satellite view of the mouth
The mouth22 km across

Sentinel-2 cloudless 2016 by EOX IT Services GmbH (contains modified Copernicus Sentinel data 2016), CC BY 4.0. The glowing line is the river as drawn by RiverATLAS.

Photos

Kymi River in pictures

Korkeakoski casting pier Kymijoki Kotka Kymenlaakso Finland 23July2023
R. Henrik Nilsson · CC BY-SA 4.0
Kymi river Kotka Kymenlaakso Finland on 20July2023
R. Henrik Nilsson · CC BY-SA 4.0

Where these numbers come from

Name, length, placesWikidata (Q890526) · CC0
Course, profile, basinRiverATLAS v1.0 (HydroATLAS, Linke et al. 2019) · CC BY 4.0 — followed from the source to the mouth given by Wikidata
FlowWaterGAP (RiverATLAS), 1971–2000 · CC BY 4.0
Climate along the riverWorldClim (RiverATLAS), 1970–2000 · CC BY 4.0
Towns, bridges, damsWikidata · CC0; GeoNames · CC BY 4.0
Along the river© OpenStreetMap contributors · ODbL
ImagesEOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons
Our other atlasesLakeyas, Coastya, Islandyas — Wikidata · CC0; © OpenStreetMap contributors · ODbL; GeoNames · CC BY 4.0; HydroLAKES · CC BY 4.0; NOAA OISST

Every source and licence is on the data sources page.

The family

Do you prefer beaches, lakes, mountains, waterfalls, islands, rivers or canyons?

Same idea, other landscapes: field atlases built on open data, month by month, in seven languages.

beachesCoastyaFind your beach: sea temperature, sun and swimming month by month.Visit
lakesLakeyasEvery lake on Earth: water temperature, ice, depth and the shore.Coming soonVisit
mountainsPeakyasEvery summit in 3D: summit weather, the 0 °C line, huts and trails.Visit
waterfallsCascadyasEvery waterfall: height, flow month by month and when it roars.Coming soonVisit
islandsIslandyasEvery island from the sea up: size, sea temperature, ferries and 3D.Coming soonVisit
riversRiveryasEvery river from source to sea: the journey, the flow and the basin in numbers.You are here
canyonsCanyonyasEvery canyon cut to scale: depth to the floor, rim and floor temperatures, trails and viewpoints.Coming soonVisit