Lake Sils and the best lakes near Sils Maria: swimming, water temperature and how to get there

Sils Maria sits on a green plain between two of the biggest lakes in the Alps: Lake Sils on one side, Lake Silvaplana on the other. One honest warning before you pack a swimsuit. Both big lakes lie close to 1,800 metres and stay cold all summer, while a handful of small moor lakes a short ride away warm to a comfortable 20 degrees.

This guide starts with the water temperature of Lake Sils month by month, then sorts every swimmable lake near Sils Maria by what it does best. Planning a first visit? Our guide to a quiet summer escape in Sils Maria covers the rest of the village.

Water temperature of Lake Sils, month by month

Lake Sils sits at 1,797 metres, drops to 71 metres deep and takes meltwater from the Vadrec da Fedoz glacier. That keeps it cold. The surface warms slowly through June, peaks for about six weeks either side of the start of August, then falls away fast. These are typical shore temperatures, not daily readings.

• May: 6 to 9 degrees. Too cold to swim without a wetsuit.
• June: 10 to 13 degrees. Short dips only, best on a still, sunny morning.
• July: 14 to 17 degrees. The first genuinely swimmable weeks.
• August: 15 to 17 degrees. The warmest and the most reliable month.
• September: 12 to 14 degrees. Bracing, and the light is at its best.
• October: 8 to 10 degrees. Shoreline walking weather, not swimming weather.

Lake Silvaplana behaves almost identically, a degree cooler in early summer and rarely above 17 degrees in August. If you want warm water rather than cold, the moor lake Lej Marsch passes 20 degrees in high summer, and that is the difference between a gasp and a swim. Engadin St. Moritz Tourism keeps an overview of the region's bathing lakes. No official service publishes a daily reading for Lake Sils itself, so ask at reception before you set off.

Lake Sils: the lake on your doorstep

Lake Sils, Lej da Segl in Romansh, begins a few minutes on foot from the village. At 4.1 square kilometres it is the largest lake in Graubünden, ringed by larch forest and overlooked by Piz Corvatsch and Piz da la Margna.

• Where to swim: the Chastè peninsula, a wooded finger of land with small sheltered bays of very clear water.
• Water temperature: 14 to 17 degrees in July and August. A short, sharp swim, not a lazy float.
• Access from Sils Maria: the marked circuit to the tip of the peninsula and back is 4.4 kilometres with 49 metres of climb, a little over an hour at an easy pace.
• Facilities: none. Bring what you need and take it home again.
• One thing to know: the Nietzsche memorial stone stands near the end of the peninsula, so the swim and the walk come as a pair.

Rowing boats, kayaks and paddle boards are rented at the boathouse in Sils and at Plaun da Lej, and we can arrange SUP rental. Paddle in the morning, because the Maloja wind arrives shortly before midday. For the laziest day of all, take the boat: Chastè is one of five landing stages on the Lake Sils boat line, Europe's highest scheduled service, running daily from 13 June to 18 October 2026 and crosses to Maloja in 40 minutes. Sils publishes the current timetable.

Lake Silvaplana: watch the kitesurfers, then brave a quick dip

Walk the other way out of Sils and you reach Lake Silvaplana, at about 1,790 metres. Swimming is possible from the grassy shores, best in the still of the morning, because this lake's real summer show starts around midday.

• Where to swim: the grassy shoreline towards Surlej, entering slowly from the bank.
• Water temperature: 12 degrees in June, 16 to 17 degrees at the August peak.
• Access from Sils Maria: the Engadin bus along the valley road, or five kilometres by bike.
• Facilities: lakeside terraces and a shore path, no supervised bathing area.
• One thing to know: the Maloja wind sets in shortly before noon and eases only late in the afternoon, turning the lake into one of Europe's great kitesurfing arenas. Watching from the shore path is the best free show in the valley.

Lej Marsch and Lej Nair: the warm moor lakes

For an actual, comfortable swim, head for the two small moor lakes in the woods between Surlej and St. Moritz Bad. Their shallow, dark water absorbs the sun and warms far beyond anything the big lakes manage.

• Where to swim: Lej Marsch has a small sandy beach on its northern bank and a jetty to jump from. Lej Nair, the black lake, is ten minutes further on foot and much quieter.
• Water temperature: above 20 degrees at Lej Marsch in high summer, the warmest swim in the valley.
• Access from Sils Maria: bus to St. Moritz Bad, Campingplatz, or five minutes on foot from the Olympiaschanze car park.
• Facilities: at Lej Marsch, fire pits with firewood, picnic areas, lounging meadows and toilets, all free. Lej Nair has a fire pit and benches, nothing more.
• One thing to know: both lie in a protected high moor, so keep to the marked paths and designated bathing areas. Neither is supervised.

Lej da Staz: the classic Engadin bathing lake

If you want the full bathing-lake experience, Lej da Staz in the Staz forest is the most famous in the Engadin and the easiest half day of the lot.

• Where to swim: from the wooden jetty, with a floating raft moored offshore for anyone who wants a target.
• Water temperature: 20 degrees and more in summer, despite sitting above 1,800 metres.
• Access from Sils Maria: bus to St. Moritz, then about 45 minutes on foot through the forest or 20 minutes on a rental e-bike. There is no car access at all.
• Facilities: changing cabins, toilets, fire pits, a playground and the Hotel Restorant Lej da Staz. Entry is free.
• One thing to know: it is busy in August. Go before eleven for a quiet meadow.

Lägh da Cavloc: a swim at the end of a walk

The most satisfying swim near Sils Maria is the one you walk for.

• Where to swim: the shallow southern shore of Lägh da Cavloc, where a small beach warms faster than the big valley lakes.
• Access from Sils Maria: boat or bus to Maloja, then an easy 3.2 kilometre trail into Val Forno, 121 metres of climb and just under an hour to the lake at 1,907 metres.
• Facilities: Restaurant Cavloccio sits at the shore and serves through the summer.
• One thing to know: a footpath loops the lake in about half an hour. Build it into the day.

Getting to the lakes without a car

You do not need a car for any of this. The Engadin bus runs the length of the valley, the boat covers Lake Sils from mid June to mid October, and e-bikes shrink the rest. Pack a towel, a warm layer and water shoes. None of these lakes has a lifeguard, so enter slowly and stay near the shore. If the water wins on the day, our easy panoramic walks around Sils Maria take in the same views on dry land.

Where to stay between the lakes

Schweizerhof, Sils Maria, a Faern collection resort, stands in the village centre, minutes on foot from Lake Sils and a short ride from every lake here. Open for summer from 3 July to 25 October 2026. If you would like the lakes on your doorstep, have a look at the hotel and our other Sils Maria experiences.

FAQ

Can you swim in Lake Sils?

Yes, most often in the sheltered bays of the Chastè peninsula. The water stays cold all summer and no shore is supervised, so plan a short dip rather than a long swim.

How warm is Lake Sils in July?

Typically 14 to 17 degrees at the surface near the shore, with August marginally warmer and steadier. The lake sits at 1,797 metres and takes glacier meltwater, which caps how warm it can get.

Which lake near Sils Maria is warmest?

Lej Marsch, the moor lake above St. Moritz Bad, which passes 20 degrees in high summer. Lej Nair and Lej da Staz are close behind, and all three are far warmer than the two big valley lakes.