Bananal Island

Island World's largest river island in Brazil's Araguaia basin

On the Araguaia River in Tocantins, Bananal is the world’s largest river island, defined by seasonal flooding, wetlands and ranching. Visitors take boat safaris for wildlife, fishing and river landscapes.

Main image

Bananal Island is a vast river island in the Araguaia River in Tocantins state, Brazil, and is the largest fluvial (river) island on Earth. Its landscape is a mix of seasonally flooded savanna, river channels, and riparian forest, with extensive wetlands and inland watercourses.

The island’s scale is striking - it stretches roughly 350 km in length and reaches several dozen kilometres in width in places, with an area on the order of 19,000 square kilometres. Highlights for visitors and researchers include wide river channels, seasonal wetlands that attract waterbirds, and traditional riverine and indigenous communities.

Bananal has been designated in parts as protected area and indigenous territory to conserve its ecosystems and support traditional livelihoods. Access is primarily by boat on the Araguaia River and conditions vary strongly with the seasonal flood cycle.

Geographically the island lies within the Araguaia basin in central Brazil; the nearest regional towns and transport links are on the river margins outside the island itself.

  • Size: Roughly 350 km long and up to about 55 km across in places, with a total area on the order of 19,000 square kilometres, making it the largest fluvial island in the world.

What to See #

  • Protected areas: Araguaia National Park and protected wetlands occupy parts of the island, protecting extensive seasonally flooded savanna and aquatic habitats.
  • Indigenous areas: Indigenous territories and small traditional communities are located mainly along inland channels and the island's margins, maintaining local riverine livelihoods.
Bananal Island
-11.3661, -50.3155

Tips for Visiting Bananal Island #

  • Arrange river transport and a local guide in advance - Bananal Island is accessed by boat along the Araguaia and much of the island is protected or indigenous land, so guide services will handle navigation, permissions and safe landing spots.
  • Visit in the drier season (roughly May-October) when sandbanks, river beaches and trails are exposed and wildlife viewing is easier; in the wetter months large areas of the island flood and access is limited.
  • Respect protected and indigenous areas: parts of Ilha do Bananal are national park or indigenous territory, so obtain any necessary permits, follow your guide's instructions and avoid entering restricted villages or sacred sites.

Best Time to Visit Bananal Island #

For Bananal Island, choose the dry season (roughly May-October) for easier land access and walking; the wet season transforms the landscape and is better for boat-based wildlife viewing.

Dry season
May-October · ~24-32 °C
Lower river levels and more exposed sandy areas - easier to walk and explore islands and floodplains by foot or vehicle.
Wet season
November-April · ~25-32 °C
Rising river levels and extensive flooding that turn parts of the island into waterways; travel is typically by boat and river scenery/ wildlife viewing can be excellent.

Weather & Climate near Bananal Island #

Climate

Bananal Island's climate is classified as Tropical Savanna - Tropical Savanna climate with consistently warm temperatures year-round. Temperatures range from 18°C to 34°C. Abundant rainfall (1656 mm/year), wettest in December with a pronounced dry season.

Temperature & Rainfall
Temperature Range
34°
Warmest Month
18°
Coldest Month
Monthly Conditions

January

January is warm with highs of 32°C and lows of 22°C. Heavy rain (284 mm).

Comfort

27°
Feels Like Warm
27°C
Temperature
22° 32°

Weather

284 mm
Rainfall
1.4 m/s
Wind
Calm

February

February is warm with highs of 32°C and lows of 22°C. Heavy rain (246 mm).

Comfort

27°
Feels Like Warm
27°C
Temperature
22° 32°

Weather

246 mm
Rainfall
1.5 m/s
Wind
Calm

March

March is warm with highs of 31°C and lows of 22°C. Heavy rain (251 mm).

Comfort

27°
Feels Like Warm
27°C
Temperature
22° 31°

Weather

251 mm
Rainfall
0.9 m/s
Wind
Calm

April

April is warm with highs of 32°C and lows of 22°C. Significant rainfall (122 mm).

Comfort

27°
Feels Like Warm
27°C
Temperature
22° 32°

Weather

122 mm
Rainfall
0.9 m/s
Wind
Calm

May

May is warm with highs of 32°C and lows of 21°C. Light rainfall.

Comfort

26°
Feels Like Warm
26°C
Temperature
21° 32°

Weather

22 mm
Rainfall
1.4 m/s
Wind
Calm

June

June is warm with highs of 32°C and lows of 18°C. Almost no rain.

Comfort

25°
Feels Like Warm
25°C
Temperature
19° 32°

Weather

5 mm
Rainfall
1.5 m/s
Wind
Calm

July

July is warm with highs of 32°C and lows of 18°C. The driest month with just 4 mm.

Comfort

25°
Feels Like Warm
25°C
Temperature
18° 32°

Weather

4 mm
Rainfall
1.6 m/s
Wind
Calm

August

August is warm with highs of 34°C and lows of 19°C. Almost no rain.

Comfort

26°
Feels Like Warm
26°C
Temperature
19° 34°

Weather

6 mm
Rainfall
1.7 m/s
Wind
Calm

September

September is the warmest month with highs of 34°C and lows of 21°C. Moderate rainfall (42 mm).

Comfort

28°
Feels Like Warm
28°C
Temperature
21° 34°

Weather

42 mm
Rainfall
1.6 m/s
Wind
Calm

October

October is the warmest month with highs of 33°C and lows of 22°C. Significant rainfall (146 mm).

Comfort

28°
Feels Like Warm
28°C
Temperature
22° 33°

Weather

146 mm
Rainfall
1.6 m/s
Wind
Calm

November

November is warm with highs of 33°C and lows of 22°C. Heavy rain (226 mm).

Comfort

27°
Feels Like Warm
27°C
Temperature
22° 33°

Weather

226 mm
Rainfall
1.0 m/s
Wind
Calm

December

December is warm with highs of 32°C and lows of 22°C. The wettest month with heavy rain (302 mm).

Comfort

27°
Feels Like Warm
27°C
Temperature
22° 32°

Weather

302 mm
Rainfall
1.4 m/s
Wind
Calm

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