Dashboard / Lake / Lac d'Annecy, Plage de la Brune
Lac d'Annecy, Plage de la Brune
The cleanest large lake in France, fed by Alpine snowmelt and filtered through a limestone aquifer — clear enough that the 30 m depth line is visible from a paddleboard.
Monthly water temperature temperature
The surface runs about 21 °C in August. The annual low is 5 °C in January and the high is 21 °C in July. The summer thermocline sits at about 8 m, where the temperature drops sharply. For October, the mean surface figure is 14.5 °C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 5 | 5 | 6.5 | 10 | 14.5 | 18.5 | 21 | 21 | 18.5 | 14.5 | 10 | 6.5 |
Safety safety
Annecy has been monitored under the French bathing-water directive since 1996 and has returned 'Excellent' every single year. The catchment is a protected nature reserve and the lake is the drinking-water source for the town, so agricultural input is tightly controlled.
Safety notes (3)
- The lake is 65 m deep and there is a real thermocline at about 8 m. Even in August, duck-diving below 10 m puts you in 11 °C water.
- Afternoon wind from the valley (the 'bise') builds quickly from 15:00 and can push a swimmer 200 m offshore. Swim upwind on the outbound leg.
- Motorboats are banned near the shore but sailing and pedal boats are not. Keep inside the 100 m swimming buoy line.
Where to get in
- Grass-to-gravel beach — La Brune beach proper; 60 m of gentle shelf, lifeguarded in season, the family entry.
- Pontoon ladder — Ladder at the end of the small pontoon, 2.5 m depth; best for a straight training swim.
On site
- Beach snack bar (July–August) and pedal boat hire
- Showers and changing rooms at the beach entrance, free
- Lifeguard station 10:00–18:00, 15 June–15 September
Getting there arrival · entry · exit
Getting there
La Brune is on the D909 between Annecy and Talloires, 8 km from town. Park on the lake side of the road where there is a gap in the barrier; the beach is signed and 2 minutes' walk.
The 40 km cycle path around the lake passes directly behind the beach, which makes La Brune the easiest car-free access point on the whole shoreline.
Getting in
The shelf is so gradual that you can walk out 40 m and still be on tiptoe. Start swimming when you choose to, not because the bottom forces you.
Because the water is 21 °C in August, this is a genuinely long-distance swim site: the standard local route is 1 km along the shore towards Talloires and back, roughly 35 minutes at a steady pace.
Getting out
Walk out anywhere along the beach — there is no drop and no weed. The showers at the beach entrance run cold, which is what you want after 21 °C water.
The snack bar stays open until 19:00 in July and August. Outside those months bring your own water; there is nothing within 2 km.
Depth profile
Grassed and gravelled shore with a 1:15 shelf to 2 m, then a long plateau of 4–8 m extending 150 m offshore. The 65 m maximum is in the middle of the lake, well beyond swimming range. Water clarity means you can watch the bottom slope away for the first 40 m of your swim.
Season window
June to September; the lake is monitored and lifeguarded from 15 June to 15 September
Cold-water questions
- Is Annecy the cleanest lake in France?
- It has returned an Excellent bathing-water classification every year since monitoring began in 1996, which no other large French lake matches.
- How warm does Lake Annecy get?
- About 21 °C in the top two metres in late July and August; below the 8 m thermocline it stays at 9–11 °C all summer.
Before you get in
Cold water is the one hazard that applies everywhere in this library. Below 15 °C the gasp reflex can make you inhale water involuntarily within seconds of immersion; below 10 °C, unacclimatised swimmers lose the ability to swim effectively within minutes. Enter gradually, keep your first session under five minutes, never swim alone, and get out while you still feel fine — the afterdrop continues after you leave the water.
Informational only. Stillwater is not a safety authority, a lifeguard service or a medical source, and nothing here is professional advice. Water conditions change within hours: temperatures are monthly means, not today's reading, and depth profiles are typical rather than surveyed. Before you enter any water, check the current conditions, read the on-site signage, follow the advice of local lifeguards above anything on this page, and if you are unsure of your ability in cold water, do not go in.
Other spots of the same water type
| Lake Bled, Velika Zaka | Gorenjska, Slovenia | 29.5 m | 15.5° October |
| Walchensee, Urfeld shore | Bavaria, Germany | 190 m | 13° October |
| Buttermere | Lake District, England | 23 m | 11° October |
| Fuxian Lake, Luchong shore | Yunnan, China | 155 m | 19° October |