Lake · Norway
Femsjøen
Lake in Halden, Norway
- Area
- 10.7km²
- Average depth
- 16m
- Elevation
- 80m a.s.l.
- Shoreline
- 33km
- Volume
- 0.173km³
Femsjøen is a lake in Norway. It covers 10.7 km². On average it is 16 m deep. Its surface lies 80 m above sea level.
Plan your visit
Stay, sail and get there
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The water
How warm is Femsjøen?
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 July to August: brisk, refreshing swimming.
The lake usually freezes over for about 36 days a year, from around 25 January to 1 March.
On the shore, afternoons reach 20 °C on average in July and 0 °C in January. The driest month is March (54 mm of rain), the wettest October (109 mm).
Average surface temperature measured by the Landsat 8 satellite between 2013 and 2021 at the point furthest from the shore (109 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 | -3 | 84 | 14 | 0.4 | 13 |
| February | Ice | — | 0 | -4 | 63 | 12 | 1.8 | 12 |
| March | 1 | 3 | 4 | -2 | 54 | 11 | 4.8 | 11 |
| April | 5 | 8 | 9 | 3 | 56 | 10 | 6.6 | 10 |
| May | 11 | 14 | 14 | 8 | 72 | 11 | 8.1 | 10 |
| June | 16 | 18 | 18 | 12 | 78 | 13 | 9.3 | 10 |
| July | 20 | 20 | 20 | 14 | 93 | 14 | 8.1 | 10 |
| August | 19 | 20 | 19 | 14 | 107 | 15 | 6.6 | 10 |
| September | 15 | 17 | 16 | 10 | 88 | 13 | 5.1 | 12 |
| October | 10 | 13 | 10 | 6 | 109 | 16 | 2.5 | 12 |
| November | 6 | 8 | 5 | 2 | 100 | 15 | 0.8 | 13 |
| December | 3 | 4 | 2 | -2 | 87 | 15 | 0.3 | 13 |
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 13 months before flowing out.
- Its catchment drains 314 km² of land.
- About 5.0 m³ of water flow out every second, on average.
- Its shoreline is 2.9 times longer than a circle of the same area: plenty of bays and inlets.
Around the shore
What's around Femsjøen
Counted within 1.5 km of the shoreline in OpenStreetMap, the map anyone can edit.
- 4beaches and swimming spots
Vanninga
- 1campsites
Bobilparkering Brekke
- —boat hire and water-sport clubs
- 2marinas and slipways
- 1ferry piers
MS Brekke
- —viewpoints
- 1hotels, B&Bs and chalets
Fløterhytta
- —fishing spots
- 2restaurants and cafés
Nearest airport with scheduled flights: Sandefjord Airport, Torp (TRF), 70 km in a straight line.
Car hire at TRF airport (Sandefjord)Discover Cars · Affiliate linkOpenStreetMap 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 | 0.4 | 0.5 | 3.8 | 9.3 | 14.3 | 18.0 | 20.1 | 19.2 | 15.5 | 9.9 | 5.3 | 1.8 |
| 2020 | +5.2 | +4.1 | +1.4 | +0.7 | −1.4 | +2.9 | −2.4 | +1.2 | +0.4 | +1.2 | +2.8 | +1.5 |
| 2021 | −2.7 | −2.1 | +1.5 | −0.8 | −1.4 | +1.4 | +2.1 | −0.3 | +0.5 | +1.8 | +0.8 | −2.7 |
| 2022 | +2.8 | +3.2 | +2.1 | −0.3 | −0.1 | +1.4 | ±0.0 | +1.5 | ±0.0 | +2.0 | +1.4 | −1.8 |
| 2023 | +1.9 | +3.2 | −0.8 | +0.5 | +1.2 | +3.2 | −1.7 | −0.3 | +2.2 | −1.0 | −3.4 | −2.9 |
| 2024 | −2.1 | +1.0 | +1.1 | −0.9 | +4.0 | −0.3 | −0.9 | ±0.0 | +1.3 | +1.7 | +1.0 | +2.4 |
| 2025 | +1.4 | +0.9 | +2.3 | +2.5 | ±0.0 | −0.4 | +2.7 | +0.1 | +1.4 | +1.0 | +1.1 | +2.7 |
+1 warmer than usual −1 cooler than usual
SwedenAbout 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 (Q3356686) · 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.
