Lake · Finland
Iisvesi
Lake in Tervo, Northern Savonia, Finland
- Area
- 277km²
- Max depth
- 35m
- Average depth
- 14m
- Elevation
- 87m a.s.l.
- Shoreline
- 557km
- Volume
- 3.8km³
Iisvesi is a lake in Finland. It covers 277 km². On average it is 14 m deep, and 35 m at its deepest point. Its surface lies 87 m above sea level.
Plan your visit
Stay, sail and get there
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The water
How warm is Iisvesi?
The water is warmest in July, around 20 °C at the surface, and coldest in January, around 0 °C. The surface averages 20 °C or more in July: comfortable for most swimmers.
The lake usually freezes over for about 156 days a year, from around 10 November to 14 April.
On the shore, afternoons reach 21 °C on average in July and -8 °C in January. The driest month is March (43 mm of rain), the wettest July (117 mm).
Average surface temperature measured by the Landsat 8 satellite between 2013 and 2021 at the point furthest from the shore (108 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 | Ice | — | -8 | -14 | 54 | 13 | 0.7 | 11 |
| February | Ice | — | -7 | -13 | 44 | 11 | 2.2 | 11 |
| March | Ice | — | -2 | -8 | 43 | 11 | 5.6 | 12 |
| April | 1 | 4 | 5 | -1 | 52 | 12 | 6.8 | 11 |
| May | 9 | 13 | 13 | 6 | 79 | 14 | 7.9 | 11 |
| June | 16 | 19 | 18 | 11 | 97 | 16 | 8.8 | 10 |
| July | 20 | 20 | 21 | 14 | 117 | 18 | 7.9 | 9 |
| August | 19 | 20 | 19 | 12 | 90 | 17 | 6.5 | 9 |
| September | 14 | 17 | 13 | 7 | 80 | 14 | 3.7 | 10 |
| October | 7 | 11 | 5 | 1 | 74 | 15 | 1.2 | 10 |
| November | Ice | — | -1 | -5 | 70 | 14 | 0.1 | 10 |
| December | Ice | — | -5 | -10 | 65 | 14 | 0.2 | 11 |
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 3.4 years before flowing out.
- Its catchment drains 3,774 km² of land.
- About 36 m³ of water flow out every second, on average.
- Its shoreline is 9.4 times longer than a circle of the same area: plenty of bays and inlets.
Around the shore
What's around Iisvesi
Counted within 1.5 km of the shoreline in OpenStreetMap, the map anyone can edit.
- 5beaches and swimming spots
Karttulanlahden uimaranta
- 5campsites
Matkaparkki, Koski Caravan
- —boat hire and water-sport clubs
- 13marinas and slipways
Karttulanlahden venesatama, Paimelan venesatama, Kerkonkosken satama and 10 more
- —ferry piers
- 2viewpoints
Lintuniemi, Autuaankannas
- 4hotels, B&Bs and chalets
Koskisydän Oy
- —fishing spots
- 8restaurants and cafés
Towns on the shore
- Karttula3,383 people
- Tervo1,398 people
Nearest airport with scheduled flights: Kuopio Airport (KUO), 48 km in a straight line.
OpenStreetMap is built by volunteers: when a number is low, it may just mean nobody has mapped it yet.
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 | -8.4 | -6.9 | -2.1 | 5.1 | 13.4 | 17.8 | 21.0 | 18.8 | 13.1 | 4.8 | -1.2 | -5.3 |
| 2020 | +7.4 | +4.9 | +2.9 | −1.2 | −2.5 | +3.5 | −2.2 | ±0.0 | +0.8 | +2.0 | +2.8 | +1.5 |
| 2021 | −2.5 | −3.9 | −0.3 | +0.7 | −0.7 | +4.4 | +2.7 | −1.3 | −2.9 | +1.9 | ±0.0 | −3.8 |
| 2022 | +1.6 | +2.7 | +0.9 | −1.8 | −1.1 | +1.7 | ±0.0 | +2.1 | −2.0 | +2.0 | −0.7 | −1.1 |
| 2023 | +3.6 | +2.1 | −1.1 | −2.3 | +0.3 | +1.6 | −1.7 | +1.3 | +3.2 | −1.8 | −4.6 | −4.3 |
| 2024 | −2.7 | +0.1 | +1.0 | −3.5 | +2.7 | +3.0 | +1.1 | +1.6 | +3.7 | +2.5 | +1.9 | +1.3 |
| 2025 | +2.5 | +2.5 | +3.4 | +1.6 | −1.5 | −0.8 | +2.7 | −0.4 | +2.5 | +2.0 | +2.5 | +3.1 |
+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 (Q1346320) · 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.
