Lake · Japan
Lake Sai
Lake in Fujikawaguchiko, Chūbu region, Japan
- Area
- 2.0km²
- Max depth
- 73m
- Average depth
- 19m
- Elevation
- 899m a.s.l.
- Shoreline
- 8.4km
- Volume
- 0.038km³
Lake Sai is a lake in Japan. It covers 2.0 km². On average it is 19 m deep, and 73 m at its deepest point. Its surface lies 899 m above sea level.
Plan your visit
Stay, sail and get there
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The water
How warm is Lake Sai?
The water is warmest in August, around 24 °C at the surface, and coldest in February, around 4 °C. The surface averages 20 °C or more from June to September: comfortable for most swimmers.
It does not normally freeze in winter.
On the shore, afternoons reach 28 °C on average in August and 4 °C in January. The driest month is January (61 mm of rain), the wettest July (209 mm).
Average surface temperature measured by the Landsat 8 satellite between 2013 and 2021 at the point furthest from the shore (61 readings). Shallow bays and beaches are often warmer.
From above
The whole lake from space
Month by month
The year at the lake, month by month
Not a forecast: these are averages over many years. Water is the 2013–2021 average; air, rain, sun and wind are the 1991–2020 average.
Water: 2013–2021 averageClimate: 1991–2020 average
| Month | Water°C | Water high°C | Air high°C | Air low°C | Rainmm | Rainy daysdays | Sunh/day | Windkm/h |
|---|---|---|---|---|---|---|---|---|
| January | 4 | 5 | 4 | -6 | 61 | 6 | 6.1 | 9 |
| February | 4 | 4 | 5 | -4 | 71 | 7 | 6.1 | 9 |
| March | 6 | 7 | 9 | -2 | 115 | 10 | 6.1 | 10 |
| April | 10 | 12 | 15 | 4 | 127 | 10 | 6.2 | 10 |
| May | 16 | 18 | 20 | 9 | 140 | 13 | 6.1 | 9 |
| June | 21 | 23 | 23 | 14 | 174 | 16 | 4.2 | 7 |
| July | 24 | 25 | 27 | 18 | 209 | 18 | 4.5 | 8 |
| August | 24 | 25 | 28 | 19 | 159 | 17 | 5.6 | 7 |
| September | 21 | 23 | 24 | 15 | 201 | 15 | 4.6 | 8 |
| October | 16 | 19 | 18 | 9 | 193 | 11 | 4.6 | 8 |
| November | 11 | 14 | 13 | 3 | 85 | 8 | 5.4 | 8 |
| December | 7 | 8 | 6 | -3 | 64 | 7 | 5.8 | 9 |
Water: LakeTEMP (Landsat 8, 2013–2021). Air, rain, sun and wind: NASA POWER, 1991–2020 averages. A rainy day has at least 1 mm of rain. Sunshine hours are derived from measured solar radiation.
Size & depth
How big, how deep
- On average, water stays in the lake for about 16 months before flowing out.
- Its catchment drains 30 km² of land.
- About 0.9 m³ of water flow out every second, on average.
Around the shore
What's around Lake Sai
Counted within 1.5 km of the shoreline in OpenStreetMap, the map anyone can edit.
- 1beaches and swimming spots
- 1campsites
Saiko Jiyū Campsite
- —boat hire and water-sport clubs
- —marinas and slipways
- —ferry piers
- 4viewpoints
Sankodai, Ashiwadayama View Point
- 3hotels, B&Bs and chalets
Kuwarubi
- —fishing spots
- 7restaurants and cafés
Towns on the shore
- Fujikawaguchiko26,540 people
- Narusawa2,824 people
Nearest airport with scheduled flights: Mount Fuji Shizuoka Airport (FSZ), 90 km in a straight line.
Car hire at HND airport (Tokyo)Discover Cars · Affiliate linkOpenStreetMap is built by volunteers: when a number is low, it may just mean nobody has mapped it yet.
Photos
Seen by visitors
Recent years
How each month compared
Afternoon high on the shore. The first row is the reference, the 1991–2020 average in °C; the years below show the difference from it: warmer in orange, cooler in blue.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1991–2020 average | 3.6 | 5.4 | 9.4 | 15.1 | 20.1 | 23.1 | 26.9 | 27.8 | 23.8 | 18.0 | 12.6 | 6.5 |
| 2020 | +2.4 | +1.9 | +1.4 | −1.9 | +0.5 | +1.0 | −2.3 | +1.5 | −0.1 | −0.9 | +1.7 | +0.6 |
| 2021 | +0.6 | +2.0 | +3.6 | +0.6 | +0.1 | −0.3 | −0.5 | −0.5 | −1.3 | +0.5 | ±0.0 | +0.6 |
| 2022 | ±0.0 | −1.5 | +2.0 | +1.0 | −0.4 | +0.3 | +0.3 | −0.1 | +0.6 | −1.0 | +1.5 | −0.2 |
| 2023 | +1.2 | +1.1 | +3.8 | +1.8 | +0.1 | +0.4 | +1.7 | +0.4 | +2.7 | +0.5 | +1.7 | +2.6 |
| 2024 | +2.2 | +2.4 | −0.6 | +2.4 | +0.6 | +0.4 | +2.6 | +0.5 | +2.2 | +2.2 | +1.2 | −0.1 |
| 2025 | +1.1 | −1.0 | +0.8 | +0.9 | −0.3 | +2.5 | +1.6 | +1.7 | +2.4 | +0.6 | +0.4 | +1.8 |
+1 warmer than usual −1 cooler than usual
About these numbers
| Outline, area, depth, volume | HydroLAKES v1.0 (Messager et al. 2016) · CC BY 4.0 |
|---|---|
| Water temperature and ice | LakeTEMP v1 (Korver et al. 2024), Landsat 8 2013–2021 · CC BY 4.0 |
| Air, rain, sun, wind | NASA POWER, 1991–2020 · public domain |
| Names and description | Wikidata (Q1152394) · CC0 |
| Around the shore | © OpenStreetMap contributors · ODbL |
| Images | EOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons |
Every figure is an average or a count from a public dataset. Licences and methods: data sources.
