River
Nam Ou
448 km from source to mouth · Laos.
LaosFlows into Mekong River1st longest in Laos
In numbers
Length
448km
Average flow
390m³/s
Basin
26,180km²
Drop
610m
from 889 m to 279 m
Country
1
The journey
From source to mouth
448 km of river and 0 stops on the way: 0 towns and cities on its banks, dams, bridges and the tributaries that feed it.
- 0 kmSourceat 889 m
- 448 kmMekong Riverat 279 m
Water level along the river (RiverATLAS; the height is exaggerated). Towns: GeoNames and Wikidata; bridges, dams and tributaries: Wikidata.
River in Laos
At the mouth it carries 389 m³/s on average: an Olympic pool every 6.4 seconds. It drops from 889 m to 279 m, 1.4 m per kilometre on average. Its basin covers 26,180 km², about the size of RW. 552,000 people live in it. Highest water: August; lowest: from December to March. No large dam holds it back: it is one of the world's free-flowing rivers.
Where to start
- Luang PrabangLargest city on its banks · 55,027 people
- Luang Phabang International Airport (LPQ)Nearest airport with scheduled flights, 2 km from the cityCar hire at VTE airport (Vientiane)Discover Cars · Affiliate link↗
- On the water15 ferry piers, marinas, boat rentals and boat ramps along the river (OpenStreetMap)
- From November to MarchThe best months to visit
Nam Ou, month by month
Highest water: August
Lowest water: from December to March. Best months to visit: from November to March.
From about 140 m³/s in the lowest month to 1,500 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
Nam Ou: the basin in numbers
26,058 km² of land send their water to this river. This is what lives on it.
- 552,000people live in the basin
- 21/km²people per km²
- 889maverage altitude of the basin
- 1,629mmof rain a year (basin average)
- 21.2°Caverage air temperature
- 8%protected areas
What covers the basin
- 5% Forest
- 5% Cropland
- 2% 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
Nam Ou: what you find on the way
- 5WaterfallsTad Mook, Had Sao Waterfall, 100 water falls and 2 more
- 13Ferry piersMuang Ngoy Pier, Nong Kheaw Pier and 11 more
- 2MarinasNong Kheaw Pier
From OpenStreetMap, within 2.0 km of the river. Not mapped is not the same as not there.
Cross-checked with our atlases
Nam Ou 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.
17mountains at the sourcePeakyas
Mountains at the source (17)
Within 15 km of the source, by Peakyas
- Phou Mingseusan1.5 km away
- Phou Laophou12 km away
- Phou Vunvanko5.5 km away
- Phou Houaypasa12 km away
- Phou Houayping11 km away
- Phou Namtin14 km away
- Phou Longtang11 km away
- Phou Cuniousan12 km away
9 more on PeakyasOpen Peakyas ↗
From space
The source and the mouth, seen from orbit
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
Nam Ou in pictures
Tributaries
Where it flows, and what flows into it
It flows into
Mekong River
Vietnam4,350 km15,000 m³/s
Thailand
CambodiaWhere these numbers come from
| Name, length, places | Wikidata (Q973135) · CC0 |
|---|---|
| Course, profile, basin | RiverATLAS v1.0 (HydroATLAS, Linke et al. 2019) · CC BY 4.0 — followed from the source to the mouth given by Wikidata |
| Flow | WaterGAP (RiverATLAS), 1971–2000 · CC BY 4.0 |
| Climate along the river | WorldClim (RiverATLAS), 1970–2000 · CC BY 4.0 |
| Towns, bridges, dams | Wikidata · CC0; GeoNames · CC BY 4.0 |
| Along the river | © OpenStreetMap contributors · ODbL |
| Images | EOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons |
| Our other atlases | 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.
beaches
Find your beach: sea temperature, sun and swimming month by month.Visit 
lakes
Every lake on Earth: water temperature, ice, depth and the shore.Coming soonVisit mountains
Every summit in 3D: summit weather, the 0 °C line, huts and trails.Visit 
waterfalls
Every waterfall: height, flow month by month and when it roars.Coming soonVisit 
islands
Every island from the sea up: size, sea temperature, ferries and 3D.Coming soonVisit 
rivers
Every river from source to sea: the journey, the flow and the basin in numbers.You are here
canyons
Every canyon cut to scale: depth to the floor, rim and floor temperatures, trails and viewpoints.Coming soonVisit