# Geography of Guinea-Bissau

The geography of Guinea-Bissau is that of low coastal plains bordering the Atlantic Ocean. The country borders Senegal in the north and Guinea in the southeast.

## Terrain and ecology

The terrain of Guinea-Bissau is mostly low coastal plain with swamps of Guinean mangroves rising to Guinean forest-savanna mosaic in the east. A recent global remote sensing analysis suggested that there were 1,203km² of tidal flats in Guinea-Bissau, making it the 28th ranked country in terms of tidal flat area.
Around 66 million years ago, an asteroid impact occurred 400 km of the west-African coast. The 2022 discovered Nadir buried Crater has a diameter of 9 km. The impact caused an earthquake of 6.5 magnitude and created a 1 km high tsunami. The combined forces could be an explanation for the extremely scarred coastline of Guinea-Bissau.
The lowest point on Guinea-Bissau is at sea level at the Atlantic Ocean. The highest point in Guinea-Bissau is Dongol Ronde with an elevation of 277 m (909 ft). The Conservation Atlas of Tropical Forests: Africa authored in 1992 cites Fouta Djallon at 262 m (860 ft) as the highest.
Natural resources found in Guinea-Bissau include fish, timber, phosphates, bauxite, clay, granite, limestone and unexploited deposits of petroleum. 10.67% of the land is arable and 235.6 square kilometres are irrigated.
Natural hazards include a hot, dry, dusty harmattan haze that may reduce visibility during the dry season and brush fires. Severe environmental issues include deforestation; soil erosion; overgrazing and overfishing.
Near the Senegal border there have been historic sightings of the painted hunting dog, Lycaon pictus, but that endangered canid may now be extirpated in that locale.

## Climate

Guinea-Bissau's climate is tropical. This means it is generally hot and humid. It has a monsoonal-type rainy season (June to November) with southwesterly winds and a dry season (December to May) with northeasterly harmattan winds.
Guinea-Bissau is warm all year around and there is little temperature fluctuation; it averages 26.3 °C (79.3 °F). The average rainfall for the capital city Bissau is 2,024 millimetres (79.7 in) although this is almost entirely accounted for during the rainy season which falls between June and September/October. From December through April, the country receives very little rainfall.
Climate data for Bissau, Guinea-Bissau (1974–1994) :
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °C (°F) | 36.7 (98.1) | 38.3 (100.9) | 38.9 (102.0) | 41.1 (106.0) | 39.4 (102.9) | 35.6 (96.1) | 33.3 (91.9) | 32.8 (91.0) | 33.9 (93.0) | 34.4 (93.9) | 35.0 (95.0) | 35.6 (96.1) | 41.1 (106.0) |
| Mean daily maximum °C (°F) | 31.1 (88.0) | 32.8 (91.0) | 33.9 (93.0) | 33.3 (91.9) | 32.8 (91.0) | 31.1 (88.0) | 29.4 (84.9) | 30.0 (86.0) | 30.0 (86.0) | 31.1 (88.0) | 31.7 (89.1) | 30.6 (87.1) | 31.5 (88.7) |
| Daily mean °C (°F) | 24.4 (75.9) | 25.6 (78.1) | 26.6 (79.9) | 27.0 (80.6) | 27.5 (81.5) | 26.9 (80.4) | 26.1 (79.0) | 26.4 (79.5) | 26.4 (79.5) | 27.0 (80.6) | 26.9 (80.4) | 24.8 (76.6) | 26.3 (79.3) |
| Mean daily minimum °C (°F) | 17.8 (64.0) | 18.3 (64.9) | 19.4 (66.9) | 20.6 (69.1) | 22.2 (72.0) | 22.8 (73.0) | 22.8 (73.0) | 22.8 (73.0) | 22.8 (73.0) | 22.8 (73.0) | 22.2 (72.0) | 18.9 (66.0) | 21.1 (70.0) |
| Record low °C (°F) | 12.2 (54.0) | 13.3 (55.9) | 15.6 (60.1) | 16.7 (62.1) | 17.2 (63.0) | 19.4 (66.9) | 19.4 (66.9) | 19.4 (66.9) | 19.4 (66.9) | 20.0 (68.0) | 15.0 (59.0) | 12.8 (55.0) | 12.2 (54.0) |
| Average rainfall mm (inches) | 0.5 (0.02) | 0.8 (0.03) | 0.5 (0.02) | 0.8 (0.03) | 17.3 (0.68) | 174.8 (6.88) | 472.5 (18.60) | 682.5 (26.87) | 434.9 (17.12) | 194.8 (7.67) | 41.4 (1.63) | 2.0 (0.08) | 2,022.8 (79.63) |
| Mean monthly sunshine hours | 248 | 226 | 279 | 270 | 248 | 210 | 186 | 155 | 180 | 217 | 240 | 248 | 2,707 |
| Source 1: Sistema de Clasificación Bioclimática Mundial ||||||||||||||
| Source 2: World Climate Guides (sunshine only) ||||||||||||||

## Information from the CIA World Factbook
### Location

    Western Africa, bordering the North Atlantic Ocean, between Guinea and Senegal

### Geographic coordinates

    12°00′N 15°00′W﻿ / ﻿12.000°N 15.000°W﻿ / 12.000; -15.000

### Area

   * Total: 36,125 km²
   ** country rank in the world: 134th
   * Land: 28,120 km²
   * Water: 8,005 km²

### Area comparative

   * Australia comparative: slightly more than ⁠1/2⁠ the size of Tasmania
   * Canada comparative: approximately ⁠1/2⁠ the size of New Brunswick
   * United Kingdom comparative: approximately ⁠3/5⁠ larger than Wales
   * United States comparative: approximately ⁠1/8⁠ larger than Maryland
   * EU comparative: slightly more than ⁠1/2⁠ the size of Ireland

### Land boundaries

   * Total: 762 km
   * Border countries: Guinea 421 km, Senegal 341 km

### Coastline

    350 km

### Maritime claims

   * Territorial sea: 12 nmi (22.2 km; 13.8 mi)
   * Exclusive economic zone: 200 nmi (370.4 km; 230.2 mi)

### Terrain

    Mostly low coastal plain rising to savanna in east

### Elevation extremes

   * Lowest point: Atlantic Ocean 0 m

### Natural resources

    Fish, timber, phosphates, bauxite, unexploited deposits of petroleum

### Land use

   * Arable land: 10.67%
   * Permanent crops: 8.89%
   * Other: 80.44% (2012 est.)

### Irrigated land

    223.6 km$^2$ (2003)

### Total renewable water resources

    31 km$^3$

### Freshwater withdrawal (domestic/industrial/agricultural)

   * Total: 0.18 km$^3$/yr (18%/6%/76%)
   * Per capita: 135.7 m$^3$/yr (2005)

### Natural hazards

    Hot, dry, dusty harmattan haze may reduce visibility during dry season; brush fires

### Environment—current issues

    Deforestation; soil erosion; overgrazing; overfishing

### Environment—international agreements

   * Party to: Biodiversity, Climate Change, Desertification, Endangered Species, Hazardous Wastes, Law of the Sea, Ozone Layer Protection, Wetlands
   * Signed, but not ratified: None of the selected agreements

## Extreme points

This is a list of the extreme points of Guinea-Bissau, the points that are farther north, south, east or west than any other location.
* Northernmost point – the northern section of the border with Senegal*
* Easternmost point – unnamed location on the border with Guinea immediately south-west of the Guinean village of Sofan, Gabú Region
* Southernmost point – unnamed headland on Ilha Cataque, Tombali Region
* Westernmost point - Cape Roxo at the point where the border with Senegal enters the Atlantic Ocean, Cacheu Region
* *Note: Guinea-Bissau does not have a northernmost point, the border here being formed by a parallel of latitude.