Indonesia
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).
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.
Getting there
- Naha Airport (NAH)nearest airport with scheduled flights · 107 km in a straight lineCar hire at DPS airport (Kuta, Badung)Discover Cars · Affiliate link↗
- FerriesPehe Siau - Makalehi, Ulu Siau - Buhias
- 1,685 km from the mainlanddistance to the nearest continental coast
- From January to Maybest months to go (from 30 years of averages)
Plan the trip
Ferries, stays and things to do
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
Beach with the warmest sea
29.5°C
Sawang Wala
sea in the warmest month · according to Coastya
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.
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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Afternoon high (°C) | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 |
| Night low (°C) | 27 | 27 | 27 | 28 | 28 | 27 | 27 | 27 | 27 | 28 | 28 | 28 |
| Sea (°C) | 28 | 28 | 28 | 29 | 29 | 29 | 29 | 29 | 29 | 30 | 29 | 29 |
| Rain (mm) | 196 | 152 | 149 | 130 | 167 | 187 | 165 | 94 | 88 | 120 | 154 | 183 |
| Wet days | 25 | 21 | 22 | 21 | 26 | 26 | 24 | 19 | 18 | 22 | 25 | 26 |
| Sun h/day | 6.4 | 6.9 | 7.6 | 8.2 | 8.1 | 7.2 | 7.6 | 8.4 | 8.4 | 7.7 | 7.4 | 6.8 |
| Wind (km/h) | 18 | 19 | 16 | 12 | 11 | 13 | 17 | 20 | 16 | 12 | 11 | 14 |
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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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.
Nearby
More islands nearby.
Philippines
About these numbers
| Names, area, population | Wikidata (Q1670781) · CC0 |
|---|---|
| Outline | © OpenStreetMap contributors · ODbL |
| Sea temperature | NOAA OISST v2.1 · 1991–2020 |
| Climate | NASA POWER · 1991–2020 |
| Relief, 3D model | Copernicus DEM GLO-30 · © DLR e.V., © Airbus Defence and Space GmbH, Copernicus/ESA |
| Beaches, ports, lighthouses, trails | © OpenStreetMap contributors · ODbL |
| Towns | GeoNames · CC BY 4.0 |
| Images | EOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons |
| Beaches, mountains, lakes and waterfalls | Coastya — 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.
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