Places · Geography · The Gambia
Geography of The Gambia: river, coast and climate
The Gambia is a long, narrow, low-lying country that follows the lower course of the River Gambia inland from the Atlantic coast of West Africa. It is surrounded by Senegal on three sides, covers roughly 11,300 square kilometres, and is mostly no more than about 50 km wide. The landscape is flat or gently rolling: sandy coast in the west, mangrove-fringed river and creeks, and wooded savannah and farmland rising only slightly towards the east.
Key geographic facts
| Feature | Details |
|---|---|
| Location | West Africa, on the Atlantic coast, enclosed by Senegal to the north, east and south |
| Total area | About 11,300 km², including a significant area of river water |
| Width | Typically around 20–50 km from border to border |
| Coastline | Short — roughly 80 km of Atlantic shore |
| Main river | The River Gambia, which crosses the whole country west to east |
| Highest point | An unnamed low rise in the east, only around 50–60 m above sea level |
| Climate | Tropical, with a single rainy season (roughly June/July to October) and a long dry season |
| Vegetation | Mangroves and wetlands along the river; savannah woodland and farmland inland |
Is The Gambia just a river?
Not quite, but it is close. On a map the country looks like a thin finger pushed into Senegal, and the River Gambia runs right along it. The river rises in the Fouta Djallon highlands of Guinea, flows through eastern Senegal, and then crosses the full length of The Gambia to reach the sea at Banjul. Land extends on both banks, typically for somewhere between about 10 and 25 km, so the country is a strip of river valley rather than the river alone. The River Gambia guide covers travelling on it.
How did a country form along a river?
The shape is a product of colonial history rather than natural boundaries. From the 1600s, European traders — first others and then chiefly the British — used the river as a route into the interior, with trading posts such as the fort on what is now Kunta Kinteh Island. Britain controlled the river and its banks while France expanded across the surrounding territory that became Senegal. The borders were fixed in agreements between Britain and France in the late nineteenth century, following the river closely. A popular story says the border was set at the range of a cannon fired from a gunboat on the river; it is a memorable image rather than a documented method. The history guide tells the full story.
The coastline
The Gambia's Atlantic coast runs from the river mouth at Banjul and Cape Point (Bakau) south to the Allahein River at Kartong, the border with the Casamance region of Senegal. It is a coast of long sandy beaches, low cliffs and laterite headlands, lagoons, and fishing villages such as Tanji and Gunjur. North of the river mouth, around Barra, there is a further stretch of shoreline in the North Bank Region, which includes Niumi National Park. The beaches guide and southern coast guide describe the shore in more detail.
The river, estuary and bolongs
The lower river is a wide estuary, several kilometres across near Banjul, where tides and salt water reach far inland. Salt water pushes much further upriver in the dry season than in the wet season, when fresh water from upstream pushes it back. This matters for farming: rice is traditionally grown in the freshwater stretches and floodplains upriver, while the saline lower river is dominated by mangroves.
Countless side creeks, called bolongs, branch off the main river. Lined with mangroves, they are nurseries for fish and shrimp and prime territory for birds, and many visitors explore them by pirogue. Further upriver the banks become higher and drier, with gallery forest and islands such as those in the River Gambia National Park.
Landscape and elevation
There are no mountains in The Gambia. Most of the country lies well under 50 m above sea level, and the highest ground — an unnamed point in the east — reaches only somewhere around 50–60 m. Away from the river, the land is a low sandstone plateau with sandy and lateritic soils, which drops to the floodplains and swamps that line the river. Inland the natural vegetation is Sudan–Guinea savannah: grassland with scattered trees such as baobab, silk-cotton and palms, much of it now cleared for farms and villages.
Climate zones and rainfall
The Gambia has a tropical climate with two main seasons. The dry season, roughly November to May, is sunny with almost no rain; from around December to February the dusty harmattan wind can blow from the Sahara. The rainy season usually begins in June or July and ends in October, with most rain falling in heavy storms in July, August and September.
Two broad patterns shape conditions across the country:
- Coast versus interior temperatures. Sea breezes keep the coast milder. Inland, especially in the Central and Upper River regions, dry-season afternoons are much hotter.
- Rainfall gradient. Rainfall generally decreases from the south-west towards the north-east. The south-western coastal area and the south bank tend to be the wettest parts of the country, while the north and far east tend to be drier, with a shorter rainy season. Totals vary a lot from year to year.
See the weather and climate guide and the best time to visit for what this means for a trip.
Soils, farming and land use
Most Gambians outside the coastal towns depend on farming. Groundnuts (peanuts) have long been the main cash crop, grown on the sandy upland soils alongside millet, sorghum and maize. Rice is grown in swamps and river floodplains, often by women, and cashew, vegetables and fruit are increasingly important. Fishing is a major activity on the coast and river. The economy guide puts these in context.
Wildlife and protected areas
The mix of coast, estuary, mangrove, wetland and savannah is why so many birds are found in such a small country. Protected areas include Abuko Nature Reserve, Tanji Bird Reserve, Kiang West and Niumi national parks, the River Gambia National Park and the Tanbi wetlands near Banjul. See the national parks guide and wildlife guide.
Environmental issues
- Coastal erosion. Parts of the coast, including stretches near Banjul and the resort area, have lost beach to the sea; sand mining and rising sea levels add to the pressure.
- Salinity. Salt water intruding upriver and into low-lying fields can damage rice farming, particularly in drier years.
- Deforestation. Clearing for farms, firewood and charcoal has reduced woodland cover.
- Rainfall variability. Like the rest of the Sahel margin, The Gambia is exposed to droughts and to intense storms and flooding.
Low elevation makes Banjul and other coastal areas vulnerable to sea-level rise, which is one reason climate adaptation is a policy priority.
Frequently asked questions
Where are the wettest parts of The Gambia?
Rainfall generally decreases from south-west to north-east, so the south-western coastal area and the south bank tend to be the wettest, while the north and far east are usually drier. Amounts vary considerably from year to year.
Is The Gambia just a river?
No, but the country is built around one. The Gambia is a narrow strip of land on both banks of the River Gambia, typically around 20–50 km wide, stretching inland from the Atlantic coast.
Why is The Gambia shaped like a river?
Its borders were agreed between Britain and France in the late nineteenth century, when Britain controlled the river and its banks and France controlled the surrounding territory that became Senegal.
What is the highest point in The Gambia?
The highest point is an unnamed low rise in the east of the country, only around 50–60 metres above sea level. There are no hills or mountains of any size.
How long is The Gambia's coastline?
The Atlantic coastline is short, roughly 80 km, running from the river mouth near Banjul south to Kartong, with a further stretch north of the river around Barra.
What is a bolong?
A bolong is a side creek or tributary channel off the River Gambia, usually lined with mangroves. Bolongs are important for fish and birds and are popular for boat trips.
What to read next
- Regions of The Gambia — the administrative map.
- River Gambia — travelling on the river.
- Weather and climate — month by month.
- National parks — protected landscapes.
- Facts about The Gambia — quick reference.
- Map of The Gambia — see the shape of the country.