Area comparison map:

four times the size of Washington, DC

Land boundaries:
0 km

Coastline:
419 km
[see also: Coastline country ranks ]

Maritime claims:
territorial sea: 12 nm
[see also: Maritime claims - territorial sea country ranks ]
exclusive economic zone: 200 nm
[see also: Maritime claims - exclusive economic zone country ranks ]
continental shelf: 200-m depth or to the depth of exploitation
[see also: Maritime claims - continental shelf country ranks ]

Climate:
tropical; modified by trade winds; warm season (December to May), cool season (May to December)

Terrain:
mostly flat islands with limestone bedrock formed from uplifted coral formation; others have limestone overlying volcanic rock

Elevation:
lowest point: Pacific Ocean 0 m
highest point: Kao Volcano on Kao Island 1,046 m

Natural resources:
arable land, fish

Land use:
agricultural land: 43.1% (2011 est.)
[see also: Land use - agricultural land country ranks ]
arable land: 22.2% (2011 est.)
[see also: Land use - arable land country ranks ]
permanent crops: 15.3% (2011 est.)
[see also: Land use - permanent crops country ranks ]
permanent pasture: 5.6% (2011 est.)
[see also: Land use - permanent pasture country ranks ]
forest: 12.5% (2011 est.)
[see also: Land use - forest country ranks ]
other: 44.4% (2011 est.)
[see also: Land use country ranks ]

Irrigated land:
0 sq km (2012)
[see also: Irrigated land country ranks ]

Population distribution:
over two-thirds of the population lives on the island of Tongatapu; only 45 of the nation's 171 islands are occupied

Natural hazards:
cyclones (October to April); earthquakes and volcanic activity on Fonuafo'ou

volcanism: moderate volcanic activity; Fonualei (180 m) has shown frequent activity in recent years, while Niuafo'ou (260 m), which last erupted in 1985, has forced evacuations; other historically active volcanoes include Late and Tofua

Environment - current issues:
deforestation from land being cleared for agriculture and settlement; soil exhaustion; water pollution due to salinization, sewage, and toxic chemicals from farming activities; coral reefs and marine populations threatened

Environment - international agreements:
party to: Biodiversity, Climate Change, Climate Change-Kyoto Protocol, Desertification, Hazardous Wastes, Law of the Sea, Marine Dumping, Marine Life Conservation, Ozone Layer Protection, Ship Pollution
signed, but not ratified: none of the selected agreements

Geography - note:
the western islands (making up the Tongan Volcanic Arch) are all of volcanic origin; the eastern islands are nonvolcanic and are composed of coral limestone and sand