River
Ider River
452 km from source to mouth · Mongolia.
MongoliaFlows into Selenga7th longest in Mongolia
In numbers
Length
452km
Average flow
57m³/s
Basin
24,555km²
Drop
1,074m
from 2,251 m to 1,177 m
Country
1
The journey
From source to mouth
452 km of river and 2 stops on the way: 1 towns and cities on its banks, dams, bridges and the tributaries that feed it.
- 0 kmKhangai Mountainsat 2,251 m
- 182 kmTosontsengel9,526 people
- 425 kmChuluut Rivertributary
- 452 kmSelengaat 1,177 m
Water level along the river (RiverATLAS; the height is exaggerated). Towns: GeoNames and Wikidata; bridges, dams and tributaries: Wikidata.
River in Mongolia
At the mouth it carries 57 m³/s on average: an Olympic pool every 44 seconds. It drops from 2,251 m to 1,177 m, 2.4 m per kilometre on average. Its basin covers 24,555 km², about the size of MK. 48,000 people live in it. Highest water: from July to August; lowest: from January to April. No large dam holds it back: it is one of the world's free-flowing rivers.
Where to start
- TosontsengelLargest city on its banks · 9,526 people
- Mörön Airport (MXV)Nearest airport with scheduled flights, 166 km from the city
- From June to AugustThe best months to visit
Ider River, month by month
Highest water: from July to August
Lowest water: from January to April. Freezing months (average below −4 °C): from November to March. Best months to visit: from June to August.
From about 9.6 m³/s in the lowest month to 230 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
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The basin
Ider River: the basin in numbers
43,083 km² of land send their water to this river. This is what lives on it.
- 48,000people live in the basin
- 1/km²people per km²
- 2,177maverage altitude of the basin
- 241mmof rain a year (basin average)
- -4.9°Caverage air temperature
- 17%protected areas
- 0.2%covered by lakes
- 59%permafrost
What covers the basin
- 7% Forest
- 2% Cropland
- 86% 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
Ider River: what you find on the way
- 1Waterfalls
From OpenStreetMap, within 2.2 km of the river. Not mapped is not the same as not there.
Cross-checked with our atlases
Ider 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.
1mountain at the sourcePeakyas
Mountains at the source (1)
Within 15 km of the source, by Peakyas
- Dulaan Har Uul6.6 km away
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
Ider River in pictures

Tributaries
Where it flows, and what flows into it
It flows into
SelengaTributaries (1)
In the same basin
Where these numbers come from
| Name, length, places | Wikidata (Q26301) · 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.