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Indonesia IndonesiaSangihe IslandsIsland

Siau Island

115 km² rising to 1,827 m out of the Celebes Sea.

When to go

Siau Island seen from space, cut out from the sea (Sentinel-2)
UluOndong SiauUlu Siau
N 2 km

Satellite: Sentinel-2 cloudless 2016 by EOX (CC BY 4.0). Outline and points © OpenStreetMap contributors / Natural Earth. North up.

In numbers

115km²

Area

66km

Coastline

1,827m

Highest point

Karangetang

45,804

People

30°C

Warmest sea

October

1,685km

To the mainland

When to go to Siau Island

Best for the beach from January to May.

The sea is warmest in October (30 °C) and coolest in February (28 °C). You can swim comfortably all year (21 °C or more).

Sea temperature (the water level) Air: night low to afternoon high Wet days Best months

Averages 1991–2020. Sea: NOAA OISST, the water within 35 km of the coast. Air, rain and sun: NASA POWER. Best months weigh warm afternoons (23–30 °C), sea of 24 °C or more and few wet days.

Island in Siau Tagulandang Biaro Islands Regency, North Sulawesi Province, Indonesia

Siau Island is an island in Indonesia. It belongs to Sangihe Islands. It covers 115 km², with 66 km of coastline. Its highest point, Karangetang, rises to 1,827 m. About 45,804 people live on it. The nearest mainland is 1,685 km away.

Read more on Wikipedia

Getting there

Plan the trip

Ferries, stays and things to do

Car hire at DPS airport (Kuta, Badung)Discover CarsSee 

Some links above are affiliate links: if you book through them we may earn a commission, at no extra cost to you. It never changes what the data on this page says.

On the island

What you find on Siau Island.

  • 10beaches
  • 3viewpointsPoint of view on 2 volcanos, Viewpoint Ulu - Karangetang
  • 2ferry terminalsUlu Siau ferry port, Pehe Siau ferry port
  • 1marinasWaterjet Port Ondong
  • 6named peaksBulude Ginapati, Bulude Bagangbalo, Bulude Papalumang and 3 more
  • 1volcanoesKarangetang Volcano
  • 4hotels, guesthouses and apartments
  • 7restaurants, cafés and bars

Counted in OpenStreetMap, the map anyone can edit, inside the island's outline. A low number may only mean nobody has mapped it yet.

Cross-checked with our atlases

Siau Island in our other atlases

Everything Coastya, Peakyas, Lakeyas and Cascadyas know about what lies inside Siau Island, each with its own numbers.

  • 1beachCoastya
  • 9mountainsPeakyas

  • Highest point

    1,827m

    Karangetang

    according to Peakyas

  • Beach with the warmest sea

    29.5°C

    Sawang Wala

    sea in the warmest month · according to Coastya

1 beaches

on Coastya, the beach atlas

  1. Sawang Walacove29.5°C

Open Coastya ↗

9 mountains

on Peakyas, the mountain atlas

  1. Karangetang1,827m
  2. Mount Tamata1,049m
  3. Bulude Ginapati
  4. Bulude Bagangbalo
  5. Bulude Tontonbulo
  6. Bulude Baliang
  7. Bulude Masio
  8. Bulude Papalumang

1 more on PeakyasOpen Peakyas ↗

The shape of the land.

On average the island stands 405 m above the sea. 35 % of it is below 200 m.

  • 9 %0–50 m
  • 26 %50–200 m
  • 36 %200–500 m
  • 20 %500–1,000 m
  • 9 %1,000–2,000 m

Share of the island's area in each altitude band, from the Copernicus DEM (30 m, read at 30–240 m on large islands).

Size, for real

Next to islands you may know.

Siau Island115 km²
Malta247 km²
Santorini76 km²

10 km

All outlines drawn to the same scale (Natural Earth and OpenStreetMap).

Towns on the island

  • Uluno census figure
  • Ondong Siauno census figure
  • Ulu Siauno census figure

Month by month

The weather on the island.

JanFebMarAprMayJunJulAugSepOctNovDec
Afternoon high (°C)282828282828282828282828
Night low (°C)272727282827272727282828
Sea (°C)282828292929292929302929
Rain (mm)1961521491301671871659488120154183
Wet days252122212626241918222526
Sun h/day6.46.97.68.28.17.27.68.48.47.77.46.8
Wind (km/h)181916121113172016121114

Averages 1991–2020 for the ~55 km NASA POWER cell over the island; the sea from NOAA OISST.

Recent years

Warmer and cooler years at sea.

Each month's sea temperature compared with its 1991–2020 average, in degrees.

JanFebMarAprMayJunJulAugSepOctNovDec
2020+0.7+0.5+0.4+0.4+0.7+0.5+0.6+0.4+0.2+0.3+0.7+0.7
2021+1.1+1.0+0.9+0.7+0.3+0.3+0.7+0.9+0.5+0.7+0.9+0.5
2022+0.5+0.4+0.7+0.4+0.3+0.4+0.3+0.4+0.5+0.4+0.7+0.6
2023+0.8+0.8+0.9+0.7+0.6+0.8+0.5+0.7+0.5+0.5+1.0+0.7
2024+0.7+0.4−0.2+0.2+0.6+0.4+0.4+0.5+0.5+0.3+0.7+0.4
2025+1.1+1.0+0.9+0.6+0.7+0.3+0.6+0.4+0.3+0.4+0.3+0.5

+1 warmer than usual −1 cooler than usual

Photos

Seen by visitors.

Conquest of Siau by Ternate in 1677
Anonymous Unknown author · Public domain
Danau Kapeta di Pulau Siau, Kabupaten Kepulauan Sitaro
MediaSulut ID · CC BY-SA 4.0
Mount Tamata - Siau Island
Ariefrahman · CC BY-SA 4.0
Siau Island Tarsier - Tarsius tumpara 01
Ariefrahman · CC BY-SA 4.0

Nearby

More islands nearby.

Sangihe IslandIndonesiaIndonesia552 km²1,320 m94 km awayTernate IslandIndonesiaIndonesia102 km²1,715 m305 km awayTidore IslandIndonesiaIndonesia117 km²408 m320 km awaySarangani IslandPhilippinesPhilippines35 km²94 m302 km awayHalmahera IslandIndonesiaIndonesia17,780 km²1,635 m355 km awayMorotai IslandIndonesiaIndonesia2,279 km²591 m346 km away

About these numbers

Names, area, populationWikidata (Q1670781) · CC0
Outline© OpenStreetMap contributors · ODbL
Sea temperatureNOAA OISST v2.1 · 1991–2020
ClimateNASA POWER · 1991–2020
Relief, 3D modelCopernicus DEM GLO-30 · © DLR e.V., © Airbus Defence and Space GmbH, Copernicus/ESA
Beaches, ports, lighthouses, trails© OpenStreetMap contributors · ODbL
TownsGeoNames · CC BY 4.0
ImagesEOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons
Beaches, mountains, lakes and waterfallsCoastya, Peakyas — Wikidata · CC0; © OpenStreetMap contributors · ODbL; GeoNames · CC BY 4.0; NOAA OISST

Every figure is an average, an estimate or a count from a public dataset. Licences and methods: data sources.

The family

Do you prefer beaches, lakes, mountains, waterfalls, islands, rivers or canyons?

Same idea, other landscapes: field atlases built on open data, month by month, in seven languages.

beachesCoastyaFind your beach: sea temperature, sun and swimming month by month.Visit
lakesLakeyasEvery lake on Earth: water temperature, ice, depth and the shore.Coming soonVisit
mountainsPeakyasEvery summit in 3D: summit weather, the 0 °C line, huts and trails.Visit
waterfallsCascadyasEvery waterfall: height, flow month by month and when it roars.Coming soonVisit
islandsIslandyasEvery island from the sea up: size, sea temperature, ferries and 3D.You are here
riversRiveryasEvery river from source to sea: the journey, the flow and the basin in numbers.Visit canyonsCanyonyasEvery canyon cut to scale: depth to the floor, rim and floor temperatures, trails and viewpoints.Visit