Lake · Sweden
Mjörn
Lake in Västergötland, Sweden
- Area
- 54.3km²
- Max depth
- 48m
- Average depth
- 15m
- Elevation
- 58m a.s.l.
- Shoreline
- 103km
- Volume
- 0.826km³
Mjörn is a lake in Sweden. It covers 54.3 km². On average it is 15 m deep, and 48 m at its deepest point. Its surface lies 58 m above sea level.
Plan your visit
Stay, sail and get there
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The water
How warm is Mjörn?
The water is warmest in July, around 20 °C at the surface, and coldest in February, around 0 °C. It rarely averages 20 °C, but it stays above 17 °C from June to August: brisk, refreshing swimming.
The lake usually freezes over for about 36 days a year, from around 19 January to 23 February.
On the shore, afternoons reach 21 °C on average in July and 0 °C in January. The driest month is April (51 mm of rain), the wettest August (96 mm).
Average surface temperature measured by the Landsat 8 satellite between 2013 and 2021 at the point furthest from the shore (102 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 | 0 | 1 | 0 | -4 | 76 | 14 | 0.4 | 10 |
| February | Ice | — | 1 | -4 | 57 | 12 | 1.6 | 9 |
| March | 2 | 4 | 4 | -2 | 53 | 11 | 4.8 | 9 |
| April | 6 | 9 | 11 | 2 | 51 | 10 | 7.0 | 8 |
| May | 12 | 15 | 16 | 6 | 68 | 12 | 8.4 | 8 |
| June | 17 | 19 | 19 | 10 | 90 | 15 | 9.4 | 8 |
| July | 20 | 20 | 21 | 13 | 95 | 15 | 8.2 | 8 |
| August | 19 | 20 | 20 | 12 | 96 | 16 | 6.7 | 8 |
| September | 15 | 17 | 16 | 9 | 73 | 14 | 5.1 | 9 |
| October | 11 | 13 | 10 | 4 | 92 | 16 | 2.5 | 9 |
| November | 7 | 9 | 5 | 1 | 81 | 15 | 0.7 | 9 |
| December | 3 | 4 | 2 | -2 | 81 | 16 | 0.2 | 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 20 months before flowing out.
- Its catchment drains 1,073 km² of land.
- About 16 m³ of water flow out every second, on average.
- Its shoreline is 3.9 times longer than a circle of the same area: plenty of bays and inlets.
Around the shore
What's around Mjörn
Counted within 1.5 km of the shoreline in OpenStreetMap, the map anyone can edit.
- 8beaches and swimming spots
Annekärr Badplats, Prästens brygga, Lövekulle badplats and 5 more
- 1campsites
Lövekulle camping
- —boat hire and water-sport clubs
- 2marinas and slipways
- —ferry piers
- 4viewpoints
- 2hotels, B&Bs and chalets
Villa Plantaget, Sjöviksgården
- —fishing spots
- 10restaurants and cafés
Towns on the shore
- Alingsås26,329 people
- Gråbo6,021 people
- Ingared1,703 people
- Björboholm1,036 people
Nearest airport with scheduled flights: Göteborg Landvetter Airport (GOT), 25 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 | 0.2 | 0.8 | 4.4 | 10.6 | 15.6 | 19.0 | 21.3 | 20.1 | 16.2 | 10.1 | 5.2 | 1.7 |
| 2020 | +5.4 | +3.9 | +1.4 | +0.4 | −1.7 | +3.1 | −3.2 | +2.1 | +0.9 | +1.1 | +2.8 | +1.3 |
| 2021 | −1.9 | −1.9 | +1.4 | −1.5 | −1.5 | +2.2 | +2.5 | −0.8 | +0.6 | +1.4 | +1.0 | −2.9 |
| 2022 | +3.0 | +2.4 | +2.4 | −0.9 | −0.6 | +1.3 | ±0.0 | +2.4 | −0.1 | +2.3 | +1.6 | −2.1 |
| 2023 | +2.4 | +2.8 | −0.9 | +0.1 | +1.6 | +3.8 | −2.2 | −0.9 | +2.7 | −0.6 | −2.5 | −1.8 |
| 2024 | −1.5 | +1.8 | +1.8 | −1.5 | +4.5 | −0.6 | −1.3 | +0.5 | +1.7 | +1.7 | +0.9 | +2.3 |
| 2025 | +2.1 | +0.8 | +3.0 | +2.5 | −0.9 | −0.5 | +1.9 | −0.2 | +1.5 | +1.0 | +0.4 | +2.6 |
+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 (Q1545197) · 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.
