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River

Ob

3,650 km from source to mouth · Russia.

RussiaRussiaFlows into Kara Sea3rd longest in Russia

Follow the riverMonth by month

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

In numbers

Length

3,650km

Average flow

12,500m³/s

Basin

2,990,000km²

Drop

339m

from 159 m to -180 m

Country

1

The journey

From source to mouth

3,650 km of river and 68 stops on the way: 4 towns and cities on its banks, dams, bridges and the tributaries that feed it.

159 m-180 m
Katunat 159 m0 km
Novosibirsk1,637,266 people608 km
Zharkovo0.6 km²841 km
Yagodnayatributary1,074 km
Nizhnevartovsk244,937 people1,722 km
Surgut300,367 people1,928 km
Kara Seaat -180 m3,650 km
01,0002,0003,0003,650 km
  1. 0 kmKatunat 159 m
  2. 8 kmKatuntributary
  3. 8 kmBiyatributary
  4. 17 kmChemrovkatributary
  5. 19 kmPeschanayatributary
  6. 24 kmAnuytributary
  7. 96 kmCharyshtributary
  8. 137 kmBolshaya Rechkatributary
  9. 154 kmAleytributary
  10. 162 kmBolshaya Kalmankatributary
  11. 185 kmZalomnaya Protokatributary
  12. 219 kmLosikhatributary
  13. 219 kmBarnaulkatributary
  14. 221 kmRowing Canal0.6 km²
  15. 229 kmBarnaul632,372 people
  16. 234 kmBolshaya Cheremshankatributary
  17. 234 kmKislukhatributary
  18. 234 kmPovalikhatributary
  19. 250 kmSeredchikhatributary
  20. 265 kmKasmalatributary
  21. 273 kmChumyshtributary
  22. 312 kmInyatributary
  23. 321 kmShelabolikhatributary
  24. 343 kmMerettributary
  25. 352 kmVerkhniy Suzuntributary
  26. 352 kmSlezyankatributary
  27. 360 kmSuzuntributary
  28. 374 kmChirukhatributary
  29. 382 kmUstye Stepnayatributary
  30. 416 kmAllakskaya Suyevatributary
  31. 418 kmKamenskaya Suyevatributary
  32. 432 kmRazboynayatributary
  33. 506 kmOrdatributary
  34. 533 kmIrmentributary
  35. 535 kmKarakantributary
  36. 570 kmMiltyushtributary
  37. 585 kmEltsovkatributary
  38. 605 kmBol'shaya Tulatributary
  39. 608 kmKamenkatributary
  40. 608 kmNovosibirsk1,637,266 people
  41. 639 kmStaritsatributary
  42. 653 kmChaustributary
  43. 681 kmPorostributary
  44. 730 kmOyashtributary
  45. 730 kmTulatributary
  46. 741 kmKindatributary
  47. 748 kmIksatributary
  48. 778 kmUrtamkatributary
  49. 801 kmTagantributary
  50. 818 kmUskovkatributary
  51. 818 kmChichagtributary
  52. 828 kmYunzherkatributary
  53. 841 kmZharkovo0.6 km²
  54. 864 kmTomtributary
  55. 894 kmLobachyovatributary
  56. 912 kmAndrevatributary
  57. 932 kmShegarkatributary
  58. 949 kmBrovkatributary
  59. 979 kmVerkhnyaya Anmatributary
  60. 992 kmChulymtributary
  61. 1,006 kmKrivaya Lukatributary
  62. 1,006 kmTatoshtributary
  63. 1,041 kmKortatributary
  64. 1,046 kmIstok Karya Bolshayatributary
  65. 1,046 kmKaldzhatributary
  66. 1,046 kmSondrovkatributary
  67. 1,074 kmYagodnayatributary
  68. 1,722 kmNizhnevartovsk244,937 people
  69. 1,928 kmSurgut300,367 people
  70. 3,650 kmKara Seaat -180 m

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

Second-longest river in Russia

At the mouth it carries 12,492 m³/s on average: 5.0 Olympic pools every second. It drops from 159 m to -180 m, 0.1 m per kilometre on average. Its basin covers 2,990,000 km², about the size of AR. 23.6 million people live in it. Highest water, with the snowmelt: from May to August; lowest: from January to April. Dams and reservoirs hold back a large share of its water (15% of a year's flow).

Read more on Wikipedia

Where to start

  • NovosibirskLargest city on its banks · 1,637,266 people
  • Novosibirsk Tolmachevo Airport (OVB)Nearest airport with scheduled flights, 19 km from the city
  • On the water168 ferry piers, marinas, boat rentals and boat ramps along the river (OpenStreetMap)
  • From June to AugustThe best months to visit

Ob, month by month

Highest water: from May to August

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

7,600
-20°26 mmJan
7,600
-19°19 mmFeb
7,600
-11°20 mmMar
7,600
-2°29 mmApr
22,300
6°42 mmMay
24,000
14°59 mmJun
23,800
18°70 mmJul
23,700
14°69 mmAug
14,600
8°51 mmSep
12,800
-1°48 mmOct
10,900
-11°37 mmNov
9,000
-17°29 mmDec
Water (estimated flow)Air (average) Rain (mm)Best months

From about 7,600 m³/s in the lowest month to 24,000 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

Ob: the basin in numbers

2,467,589 km² of land send their water to this river. This is what lives on it.

Heavily regulatedReservoirs can hold 15% of a year's flow: dams shape its seasons.
  • 23.6millionpeople live in the basin
  • 10/km²people per km²
  • 291maverage altitude of the basin
  • 465mmof rain a year (basin average)
  • -0.5°Caverage air temperature
  • 8%protected areas
  • 1.9%covered by lakes
  • 11%permafrost
  • 64km³held in reservoirs

What covers the basin

  • 47% Forest
  • 11% Cropland
  • 15% Pasture

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

Ob: what you find on the way

  • 64Dams
  • 4Weirs
  • 10Locks
  • 2Waterfalls
  • 11Boat ramps
  • 113Ferry piers
  • 41Marinas
  • 3Boat rentalsSup
  • 7River beaches

From OpenStreetMap, within 3.2 km of the river. Not mapped is not the same as not there.

Cross-checked with our atlases

Ob 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.

  • 2lakes on its wayLakeyas
  • 2mountains at the sourcePeakyas

Lakes and reservoirs (2)

Lakes it flows through, by Lakeyas

  1. Rowing Canalkm 228 · 16 m deep0.6km²
  2. Zharkovokm 8680.6km²

Lakeyas is coming soonOpen Lakeyas ↗

Mountains at the source (2)

Within 15 km of the source, by Peakyas

  1. Uval Bol'shoy7.7 km away
  2. Uval Smolenskiy14 km away

Open Peakyas ↗

From space

The source and the mouth, seen from orbit

Ob: satellite view of the source
The source14 km across
Ob: satellite view of the mouth
The mouth214 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

Tributaries (228)

IrtyshRussiaRussia4,248 km3,000 m³/sjoins at km 2,280ChulymRussiaRussia1,799 km780 m³/sjoins at km 1,023KetRussiaRussia1,621 km560 m³/sjoins at km 1,300VasyuganRussiaRussia1,082 km330 m³/sjoins at km 1,367TomRussiaRussia827 km1,100 m³/sjoins at km 891KatunRussiaRussia688 km630 m³/sjoins at km 8BiyaRussiaRussia301 km480 m³/sjoins at km 8

Also: Aley, Bolshoy Yugan, Vakh, Severnaya Sosva, Charysh, Tym, Anuy, Inya, Chumysh, Kazym, Tromyogan, Parabel, Chaya, Bolshoy Salym, Vatinsky Egan, Lyamin, Pim River, Poluy, Kievsky Yogan, Barnaulka, Shegarka, Nazym, Peschanaya, Kasmala

In the same basin

TobolRussiaRussia1,591 km800 m³/sIshimRussiaRussia2,450 km56 m³/sTuraRussiaRussia1,030 km200 m³/sOmRussiaRussia1,091 km64 m³/sTavdaRussiaRussia719 km460 m³/sIsetRussiaRussia606 km73 m³/sBukhtarma RiverKazakhstanKazakhstan336 km210 m³/sUba RiverKazakhstanKazakhstan278 km180 m³/sÜlbi RiverKazakhstanKazakhstan100 km100 m³/s

Nearby

Rivers nearby

TazRussiaRussia1,401 km930 m³/s347 km awayPurRussiaRussia389 km1,000 m³/s347 km away

Where these numbers come from

Name, length, placesWikidata (Q973) · 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, Peakyas — 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