Lake · France
Lac de Grand-Lieu
Lake in Loire-Atlantique, France
- Area
- 21.9km²
- Max depth
- 4m
- Average depth
- 1.2m
- Elevation
- -1m a.s.l.
- Shoreline
- 70km
- Volume
- 0.026km³
Lac de Grand-Lieu is a lake in France. It covers 21.9 km². On average it is 1.2 m deep, and 4 m at its deepest point. Its surface lies 1 m below sea level.
Plan your visit
Stay, sail and get there
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The water
How warm is Lac de Grand-Lieu?
The water is warmest in July, around 25 °C at the surface, and coldest in January, around 6 °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 24 °C on average in August and 9 °C in January. The driest month is September (44 mm of rain), the wettest December (93 mm).
Average surface temperature measured by the Landsat 8 satellite between 2013 and 2021 at the point furthest from the shore (66 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 | 6 | 6 | 9 | 4 | 86 | 14 | 2.0 | 20 |
| February | 7 | 8 | 10 | 3 | 65 | 11 | 3.7 | 20 |
| March | 10 | 11 | 12 | 4 | 65 | 11 | 5.0 | 19 |
| April | 14 | 16 | 15 | 7 | 50 | 11 | 6.9 | 17 |
| May | 18 | 21 | 18 | 10 | 57 | 11 | 7.5 | 16 |
| June | 23 | 25 | 22 | 13 | 46 | 9 | 8.3 | 15 |
| July | 25 | 25 | 24 | 15 | 46 | 9 | 8.3 | 16 |
| August | 24 | 25 | 24 | 15 | 48 | 9 | 7.6 | 15 |
| September | 21 | 23 | 22 | 12 | 44 | 9 | 7.0 | 15 |
| October | 15 | 18 | 17 | 10 | 82 | 14 | 4.1 | 17 |
| November | 9 | 12 | 13 | 7 | 89 | 15 | 2.8 | 19 |
| December | 6 | 7 | 10 | 4 | 93 | 14 | 2.1 | 20 |
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 22 days before flowing out.
- Its catchment drains 811 km² of land.
- About 14 m³ of water flow out every second, on average.
- Its shoreline is 4.2 times longer than a circle of the same area: plenty of bays and inlets.
Around the shore
What's around Lac de Grand-Lieu
Counted within 1.5 km of the shoreline in OpenStreetMap, the map anyone can edit.
- —beaches and swimming spots
- 1campsites
Aire de camping-cars de Passay
- —boat hire and water-sport clubs
- 1marinas and slipways
- —ferry piers
- 6viewpoints
Pierre Aigüe, Port d'hiver - Passay - Lac de Grand Lieu, Port d'été - Passay - Lac de Grand Lieu, Tour panoramique - Maison des Pêcheurs du Lac de Grand Lieu and 2 more
- —hotels, B&Bs and chalets
- —fishing spots
- 2restaurants and cafés
Towns on the shore
- Bouaye5,673 people
- La Chevrolière5,220 people
- Pont-Saint-Martin5,114 people
- Saint-Mars-de-Coutais2,360 people
Nearest airport with scheduled flights: Nantes Atlantique Airport (NTE), 7 km in a straight line.
Car hire at NTE airport (Nantes)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 | 9.2 | 9.7 | 12.4 | 15.4 | 18.4 | 22.0 | 23.7 | 23.7 | 21.6 | 17.4 | 12.9 | 9.6 |
| 2020 | +1.4 | +2.6 | +0.8 | +2.6 | +2.0 | −1.5 | +0.3 | +0.7 | +1.2 | −1.4 | +1.2 | +1.0 |
| 2021 | −1.1 | +0.6 | +0.6 | +0.2 | −1.6 | +0.7 | −0.6 | −0.5 | +1.9 | +0.5 | −1.7 | +0.9 |
| 2022 | −0.6 | +2.0 | +1.9 | +1.4 | +3.6 | +2.6 | +5.0 | +4.8 | +1.3 | +3.4 | +2.3 | −0.5 |
| 2023 | +0.5 | +0.6 | +0.4 | +0.3 | +2.1 | +3.8 | +0.2 | +1.2 | +3.9 | +3.2 | +1.2 | +2.1 |
| 2024 | −0.2 | +2.6 | +0.9 | +0.1 | −0.2 | −0.4 | −0.9 | +0.3 | −1.7 | +0.9 | +1.4 | +0.8 |
| 2025 | +0.1 | +0.7 | +0.9 | +2.2 | +2.0 | +3.5 | +2.1 | +3.4 | −0.2 | +1.3 | +1.8 | +1.1 |
+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 (Q3215452) · 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.
