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River

Oka

1,500 km from source to mouth · Russia.

RussiaRussiaFlows into Volga

Follow the riverMonth by month

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

In numbers

Length

1,500km

Average flow

1,300m³/s

Basin

245,000km²

Drop

124m

from 184 m to 60 m

Country

1

The journey

From source to mouth

1,500 km of river and 68 stops on the way: 11 towns and cities on its banks, dams, bridges and the tributaries that feed it.

184 m60 m
Sourceat 184 m0 km
Nepolod'tributary100 km
Yachenskoe Reservoir1.5 km²337 km
Kaluga324,989 people339 km
Bolshaya Smedvatributary549 km
Kolomna147,690 people585 km
Ozero Vel'ye1.3 km²751 km
Ozero Dlinnoye (lanaw sa Rusya, Ryazanskaya Oblast')0.5 km²812 km
Shomsha0.3 km²964 km
Ozero Shiverkhi0.8 km²1,062 km
Murom126,931 people1,182 km
Nizhny Novgorod1,198,245 people1,390 km
Volgaat 60 m1,500 km
05001,0001,500 km
  1. 0 kmSourceat 184 m
  2. 26 kmRakitnyatributary
  3. 26 kmTrosnatributary
  4. 51 kmItskatributary
  5. 51 kmKromatributary
  6. 70 kmTsontributary
  7. 73 kmRybnitsatributary
  8. 83 kmOrël303,696 people
  9. 89 kmOrliktributary
  10. 100 kmNepolod'tributary
  11. 105 kmOptukhatributary
  12. 162 kmZushatributary
  13. 176 kmIstatributary
  14. 182 kmNugrtributary
  15. 218 kmBelyov12,746 people
  16. 218 kmVyrkatributary
  17. 240 kmSrednyaya Vyrkatributary
  18. 254 kmUpatributary
  19. 268 kmCherepettributary
  20. 279 kmSvobodtributary
  21. 293 kmZhizdratributary
  22. 303 kmPtaratributary
  23. 319 kmVyssatributary
  24. 328 kmUgratributary
  25. 337 kmYachenskoe Reservoir1.5 km²
  26. 339 kmKaluga324,989 people
  27. 345 kmKaluzhkatributary
  28. 364 kmUzherdtributary
  29. 388 kmKomolatributary
  30. 397 kmKrushmatributary
  31. 410 kmMyshegatributary
  32. 421 kmVashanatributary
  33. 440 kmTarusa9,791 people
  34. 444 kmTarusa Rivertributary
  35. 450 kmTulovnyatributary
  36. 457 kmProtvatributary
  37. 466 kmSknigatributary
  38. 469 kmPavlenskoye Lake1.4 km²
  39. 472 kmNaratributary
  40. 482 kmPushchino21,281 people
  41. 507 kmBesputatributary
  42. 507 kmLopasnyatributary
  43. 514 kmMutenkatributary
  44. 518 kmKashira49,638 people
  45. 526 kmKashirkatributary
  46. 549 kmBolshaya Smedvatributary
  47. 579 kmOsyotrtributary
  48. 585 kmKolomna147,690 people
  49. 590 kmMoskva Rivertributary
  50. 615 kmTsnatributary
  51. 647 kmVoblyatributary
  52. 696 kmSolotchatributary
  53. 716 kmVozhatributary
  54. 751 kmOzero Vel'ye1.3 km²
  55. 769 kmRakatributary
  56. 790 kmTysyatributary
  57. 807 kmIstyatributary
  58. 809 kmPronyatributary
  59. 812 kmOzero Dlinnoye (lanaw sa Rusya, Ryazanskaya Oblast')0.5 km²
  60. 964 kmShomsha0.3 km²
  61. 1,062 kmOzero Shiverkhi0.8 km²
  62. 1,082 kmOzero Staritsa (lanaw nga porma ug arko sa Rusya, Ryazanskaya Oblast', lat 54,91, long 41,79)0.6 km²
  63. 1,158 kmPrud Doschatinskiy2.5 km²
  64. 1,182 kmMurom126,931 people
  65. 1,202 kmOzero Staryy Klyuch0.5 km²
  66. 1,265 kmKustorka lake1.6 km²
  67. 1,346 kmDzerzhinsk233,126 people
  68. 1,390 kmNizhniy Novgorod1,259,013 people
  69. 1,390 kmNizhny Novgorod1,198,245 people
  70. 1,500 kmVolgaat 60 m

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

River in Russia, tributary of Volga

At the mouth it carries 1,258 m³/s on average: an Olympic pool every 2.0 seconds. It drops from 184 m to 60 m, 0.1 m per kilometre on average. Its basin covers 245,000 km², about the size of GB. 26.9 million people live in it. Highest water, with the snowmelt: from April to July; 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

  • Nizhniy NovgorodLargest city on its banks · 1,259,013 people
  • Nizhny Novgorod / Strigino International Airport (GOJ)Nearest airport with scheduled flights, 18 km from the city
  • On the water122 ferry piers, marinas, boat rentals and boat ramps along the river (OpenStreetMap)
  • Kayak and canoe3 put-ins and rapids mapped (OpenStreetMap)
  • From May to AugustThe best months to visit

Oka, month by month

Highest water: from April to July

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 May to August.

920
-10°39 mmJan
390
-9°30 mmFeb
390
-4°28 mmMar
4,500
6°38 mmApr
4,900
13°46 mmMay
4,900
17°68 mmJun
5,000
19°84 mmJul
2,400
17°64 mmAug
2,600
12°56 mmSep
2,700
5°54 mmOct
2,000
-2°51 mmNov
1,500
-6°46 mmDec
Water (estimated flow)Air (average) Rain (mm)Best months

From about 390 m³/s in the lowest month to 5,000 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

Car hire in RussiaDiscover CarsSee 

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

Oka: the basin in numbers

244,308 km² of land send their water to this river. This is what lives on it.

Free-flowingDams upstream can hold only 1.0% of a year's flow: the river still keeps its natural rhythm.
  • 26.9millionpeople live in the basin
  • 112/km²people per km²
  • 166maverage altitude of the basin
  • 600mmof rain a year (basin average)
  • 4.7°Caverage air temperature
  • 6%protected areas
  • 0.3%covered by lakes
  • 0.4km³held in reservoirs

What covers the basin

  • 38% Forest
  • 37% Cropland
  • 14% Pasture
  • 4% 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

Oka: what you find on the way

  • 31Dams
  • 9Weirs
  • 8Locks
  • 9Waterfalls
  • 3Rapids
  • 11Boat ramps
  • 83Ferry piersDock 19, Dock 1552, Dock 148 and 80 more
  • 27Marinas
  • 1Boat rentals
  • 21River beaches

From OpenStreetMap, within 2.6 km of the river. Not mapped is not the same as not there.

Cross-checked with our atlases

Oka 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.

  • 10lakes on its wayLakeyas

Lakes and reservoirs (10)

Lakes it flows through, by Lakeyas

  1. Yachenskoe Reservoirkm 3321.5km²
  2. Pavlenskoye Lakekm 4621.4km²
  3. Ozero Vel'yekm 7411.3km²
  4. Shomshakm 9500.3km²
  5. Ozero Shiverkhikm 1,0470.8km²
  6. Ozero Staritsa (lanaw nga porma ug arko sa Rusya, Ryazanskaya Oblast', lat 54,91, long 41,79)km 1,0660.6km²
  7. Prud Doschatinskiykm 1,1412.5km²
  8. Kustorka lakekm 1,2471.6km²

2 more on LakeyasLakeyas is coming soonOpen Lakeyas ↗

From space

The source and the mouth, seen from orbit

Oka: satellite view of the source
The source14 km across
Oka: satellite view of the mouth
The mouth67 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.

Tributaries

Where it flows, and what flows into it

It flows into

VolgaRussiaRussia3,530 km8,100 m³/s

Tributaries (133)

KlyazmaRussiaRussia686 km150 m³/sjoins at km 1,286MokshaRussiaRussia656 km95 m³/sjoins at km 1,037Moskva RiverRussiaRussia473 km110 m³/sjoins at km 582

Also: Ugra, Upa, Nara, Protva, Zhizdra, Osyotr, Pronya, Tyosha, Pra, Gus, Para, Vozha, Zusha, Lopasnya, Ushna, Besputa, Tsna, Kishma, Tarusa River, Trubezh, Vyssa, Myshega, Pyot, Seyma

In the same basin

KamaRussiaRussia1,805 km4,100 m³/sBelayaRussiaRussia1,430 km950 m³/sVyatkaRussiaRussia1,314 km890 m³/sSuraRussiaRussia841 km260 m³/sUfaRussiaRussia918 km390 m³/sVetlugaRussiaRussia889 km260 m³/sSamaraRussiaRussia594 km50 m³/sChusovayaRussiaRussia735 km220 m³/sVisheraRussiaRussia415 km460 m³/sMologaRussiaRussia456 km170 m³/s

Nearby

Rivers nearby

KlyazmaRussiaRussia686 km150 m³/s65 km awaySuraRussiaRussia841 km260 m³/s126 km awayVetlugaRussiaRussia889 km260 m³/s141 km awayMokshaRussiaRussia656 km95 m³/s221 km awayMoskva RiverRussiaRussia473 km110 m³/s350 km awayKamaRussiaRussia1,805 km4,100 m³/s390 km awayCheptsaRussiaRussia501 km130 m³/s439 km awayVyatkaRussiaRussia1,314 km890 m³/s474 km away

Where these numbers come from

Name, length, placesWikidata (Q172089) · 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 — 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