River
Seym
696 km from source to mouth · Ukraine and Russia.
Ukraine and RussiaFlows into Desna7th longest in Ukraine
In numbers
Length
696km
Average flow
100m³/s
Basin
27,500km²
Drop
72m
from 184 m to 112 m
Countries
2
The journey
From source to mouth
696 km of river and 22 stops on the way: 8 towns and cities on its banks, dams, bridges and the tributaries that feed it.
- 0 kmChernihiv Oblastat 184 m
- 66 kmDonetskaya Seymitsatributary
- 74 kmSolntsevo4,374 people
- 128 kmRat'tributary
- 150 kmTuskartributary
- 168 kmVoroshnëvo3,244 people
- 177 kmPryamitsyno5,120 people
- 182 kmBol'shaya Kuritsatributary
- 209 kmKursk Reservoir19 km²
- 219 kmReuttributary
- 232 kmImeni Karla Libknekhta7,773 people
- 277 kmFitizh0.4 km²
- 301 kmSvapatributary
- 337 kmRyl’sk17,007 people
- 374 kmKrepnatributary
- 386 kmSnagosttributary
- 392 kmGlushkovo5,618 people
- 448 kmTëtkino3,852 people
- 464 kmVirtributary
- 505 kmPutyvl14,886 people
- 548 kmKleventributary
- 598 kmYezuchtributary
- 599 kmKukilkatributary
- 696 kmDesnaat 112 m
Water level along the river (RiverATLAS; the height is exaggerated). Towns: GeoNames and Wikidata; bridges, dams and tributaries: Wikidata.
River in Russia and Ukraine
At the mouth it carries 100 m³/s on average: an Olympic pool every 25 seconds. It drops from 184 m to 112 m, 0.1 m per kilometre on average. Its basin covers 27,500 km², about the size of HT. 1.3 million people live in it. Highest water: from April to June; lowest: from December to March. No large dam holds it back: it is one of the world's free-flowing rivers.
Where to start
- Ryl’skLargest city on its banks · 17,007 people
- On the water5 ferry piers, marinas, boat rentals and boat ramps along the river (OpenStreetMap)
- From May to SeptemberThe best months to visit
Seym, month by month
Highest water: from April to June
Lowest water: from December to March. Freezing months (average below −4 °C): from December to February. Best months to visit: from May to September.
From about 76 m³/s in the lowest month to 320 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
Seym: the basin in numbers
27,894 km² of land send their water to this river. This is what lives on it.
- 1.3millionpeople live in the basin
- 48/km²people per km²
- 190maverage altitude of the basin
- 608mmof rain a year (basin average)
- 6.1°Caverage air temperature
- 8%protected areas
- 0.4%covered by lakes
What covers the basin
- 4% Forest
- 61% Cropland
- 16% Pasture
- 2% 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
Seym: what you find on the way
- 7Weirs
- 2Waterfalls
- 2Ferry piers
- 1Marinas
- 10River beaches
From OpenStreetMap, within 2.1 km of the river. Not mapped is not the same as not there.
Cross-checked with our atlases
Seym 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
Lakes and reservoirs (2)
Lakes it flows through, by Lakeyas
- Kursk Reservoirkm 16019km²
- Fitizhkm 2130.4km²
Lakeyas is coming soonOpen Lakeyas ↗
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
Seym in pictures
Tributaries
Where it flows, and what flows into it
It flows into
DesnaUkraine1,130 km360 m³/sTributaries (29)
Also: Svapa, Kleven, Tuskar, Vir, Rogozna, Yezuch, Bol'shaya Kuritsa, Reut, Rat', Kukilka, Chasha, Amon'ka, Snagost, Leshchinka, Donetskaya Seymitsa, Prutishche, Mlodat, Krepna, Tolpinka, Schemlya, Byk, Polnaya, Rylo, Rzhava
In the same basin
Nearby
Rivers nearby
Ukraine253 km24 m³/s71 km awayPripyat RiverUkraine775 km460 m³/s146 km awaySozh
Belarus648 km210 m³/s132 km awaySudostUkraine208 km19 m³/s111 km awayOster RiverUkraine199 km3.2 m³/s134 km awayIputBelarus437 km83 m³/s150 km awayTeterivUkraine385 km18 m³/s165 km awayBerezinaBelarus613 km140 m³/s199 km awayWhere these numbers come from
| Name, length, places | Wikidata (Q738986) · 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 | Lakeyas — 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?
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Every island from the sea up: size, sea temperature, ferries and 3D.Coming soonVisit 
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