World Factbook
Guam
Last updated: 2026-03-28 (today)
Area
land
544 sq km
water
0 sq km
total
544 sq km
Climate
tropical marine; generally warm and humid, moderated by northeast trade winds; dry season (January to June), rainy season (July to December); little seasonal temperature variation
Terrain
volcanic origin, surrounded by coral reefs; relatively flat coralline limestone plateau (source of most fresh water), with steep coastal cliffs and narrow coastal plains in north, low hills in center, mountains in south
Land use
other
18% (2023 est.)
forest
52.4% (2023 est.)
agricultural land
29.6% (2023 est.)
agricultural land: arable land
arable land: 1.9% (2023 est.)
agricultural land: permanent crops
permanent crops: 13% (2023 est.)
agricultural land: permanent pasture
permanent pasture: 14.8% (2023 est.)
Location
Oceania, island in the North Pacific Ocean, about three-quarters of the way from Hawaii to the Philippines
Coastline
125.5 km
Elevation
lowest point
Pacific Ocean 0 m
highest point
Mount Lamlam 406 m
Irrigated land
2 sq km (2012)
Map references
Oceania
Land boundaries
total
0 km
Maritime claims
territorial sea
12 nm
exclusive economic zone
200 nm
Natural hazards
frequent squalls during rainy season; relatively rare but potentially destructive typhoons (June to December)
Geography - note
largest and southernmost island in the Mariana Islands archipelago and the largest island in Micronesia; strategic location in western North Pacific Ocean
Natural resources
aquatic wildlife (supporting tourism), fishing (largely undeveloped)
Area - comparative
three times the size of Washington, D.C.
Geographic coordinates
13 28 N, 144 47 E
Population distribution
no large cities exist on the island; large villages (municipalities) attract much of the population; the largest of these is Dededo