Lake Annecy in figures: size, visitor numbers, swimming and the Fête du Lac
14.6 km long, 1.8 million tourists in the 2024 season, an official water reading that currently gives 22.5°C on 15 September 2026, and a first Saturday in August that fills the bay. The published figures on Lake Annecy, what they cover, and the pages that go into each subject.
Lake Annecy is the most searched subject of the destination, and most pages answering it repeat "the cleanest lake in Europe". This page does something else: it gathers the published figures, says where they come from, and points to the detailed page on each subject.
Size, visitor numbers, water temperature, the lake circuit, staying and eating by the water, the Fête du Lac: each section gives the essentials and the link to the page that digs deeper.
How big is Lake Annecy?
Official bodies do not all give the same surface area, and that is the first thing to know: 26.5 to 27.6 km² depending on the method. The length is 14.6 km, the maximum width 3.2 km.
The average depth is 41 m. The maximum depth depends on what you measure: the lake authority publishes 78.7 m at the Boubioz hole, other sources go up to 82 m, and the main basin does not exceed 65 m. The details of the discrepancies are in the depth of Lake Annecy.
The lake is divided into two basins, the large lake on the Annecy side and the small lake to the south towards Duingt and Doussard. To place the shores, villages and distances, the map of Annecy sets out the geography.
How many visitors does the lake attract each year?
There is no consolidated figure for the lake as a whole. The published data cover different areas, and adding them up would be making things up.
- 2024 season, Annecy destination: 1.8 million tourists, 72% of them French and 28% from abroad, according to the tourist office as reported by the business press.
- South shore, 2025 season: 909,000 overnight stays from 26 April to 17 October 2025 in the Sources du Lac area, an increase of 6.2% on summer 2024 and 40.2% on 2020.
- Tourist office visitors, 2022: 176,000 visitors at the information offices according to the partner guide, but about 200,000 visitors, up 40% on 2021 according to the activity report for the same year.
The two 2022 figures come from the same body and do not match. We show both. Online, the office counted 1.5 million visitors and 5 million page views in 2022, then 860,000 unique visits from 197 countries in summer 2024 alone.
Summer 2024 was described as "good but not exceptional": enquiries at the information desks, 14,302 enquiries in July and 18,098 in August, were down on the two previous years. The office closed its 2024 accounts with a surplus of €318,048.98.
The lake peaks in July. The guides agree: three to four months ahead for a room by the water, and a cancellable rate costs little. The summer accommodation search for Annecy shows what is really left on your dates.
See summer availability around the lake →Partner link: booking through this link supports the site at no extra cost to you.When is the water warm enough to swim?
The tourist office's official reading, taken at the sailing club and refreshed each time this page is visited, gives 22.5°C on 15 September 2026. The swimming season runs from June to September, with peaks of 25 or 26°C in July and August in hot summers.
Unofficial websites show values that differ by several degrees on the same day, depending on whether they measure or model. Two pages go into the subject: the lake temperature month by month and today's reading and why websites contradict each other.
What happens on the first Saturday in August?
The Fête du Lac, a fireworks show over the bay of Albigny, draws more than 150,000 spectators according to the prefecture, about 200,000 according to the town. In 2026, gates opened at 7pm and the fireworks started at 9:45pm.
The 2027 date has not been published, but the first-Saturday-in-August rule makes it predictable, and ticket sales open every year in early June. The full pattern, the paid zones and the question of free viewing are in the Annecy Fête du Lac.
How do you go round the lake?
By bike, the tourist office publishes 37 km, including 33 km of cycle paths, with 250 m of climbing. Other listings say 40 or 42 km: the distance depends on the starting point and the variants on the east shore, which partly stays on the road.
Be aware that the east shore is closed to cyclists from 14 September to 18 December 2026 for roadworks, which rules out the full loop. The details are in cycling round the lake. For runners, the MaXi-Race goes round via the ridges, over 100 to 105 km in one day: see the three ways round Lake Annecy.
Where can you sleep and eat by the water?
The number of campsites around the lake depends on the area the source covers: 29 for a national directory, 12 family campsites, 6 of them less than 100 m from the shore for a local guide. And "lakeside" means a private beach or a pitch several hundred metres from the water, depending on the listing. The 2026 opening dates and recorded prices are in camping at Lake Annecy.
For restaurants, there are two pages: the terraces right on the water, shore by shore, and restaurants with a lake view, which distinguishes three formats and gives the opening seasons. The comparison of areas to stay in town is in where to stay in Annecy.
Why is the Bout du Lac nature reserve under pressure?
At the southern tip, the Bout du Lac national nature reserve has protected 84 ha of marshland since 1974. Its eco-counters recorded more than 190,000 passages in 2025, on a trail of 1.5 to 2 km, open 7am to 9pm.
Dogs and bikes are banned there, which surprises cyclists arriving along the greenway. Opening hours, access and the story of the abandoned marina project are in the Bout du Lac reserve.
What is missing from the lake's statistics?
No body publishes a crowd curve by hour or by day, whether for the beaches, the greenway or the Fête du Lac. Advice such as "come early" or "avoid Saturdays" is based on observation, not measurement.
No figure for economic spin-offs specific to the lake or the Fête is published with its method. And no source compiles occasional closures of beaches or trails: the information comes out as it happens, on signs and social media.
These gaps are not a detail. They mean that no website, ours included, can tell you how crowded a beach really is on a Saturday in July. Be wary of those that claim to.
Seeing the lake from the water changes how you read the map: cruises with or without stops, paddleboarding, sailing and kayaking leave from the quays of Annecy and the villages. The Annecy activities page gathers the options with duration and price, which saves you comparing five operators' websites.
See the activities available on Lake Annecy →Partner link: booking through this link supports the site at no extra cost to you.Sources
Office de tourisme du lac d'Annecy (activity reports for 2022, 2023 and 2024 appended to Grand Annecy decisions DEL-2023-273, DEL-2024-265 and DEL-2025-245; 2024 partner guide; spring-summer-autumn 2024 press kit; end-of-2024 review of 18 February 2025; water temperature reading), SILA (lake characteristics), Larousse and Wikipedia (dimensions).
Groupe Ecomedia (19 September 2024), G2A for the Sources du Lac d'Annecy tourist office (summer 2024 review published in December 2024, 2025 summary published in November 2025), Ville d'Annecy and Haute-Savoie prefecture (Fête du Lac 2026). Research consolidated on 12 September 2026. The areas covered by the visitor figures are not comparable with one another.
Frequently asked questions
How big is Lake Annecy?
How many tourists visit Lake Annecy?
What is the water temperature of Lake Annecy?
When is the Fête du Lac in Annecy?
How many kilometres is the Lake Annecy circuit?
Camille Perrissin
Camille grew up in Sévrier, on the west shore, and swims in the lake from April to November. She has been taking the water temperature herself since 2019 and knows where the bottom suddenly drops away. She writes about the lake without ever turning it into a postcard.
