⛱️ Where is the warmest lake for swimming in Austria in summer

Summer in Austria can be spent by the water without traveling to the sea. According to the latest EU water quality report, 96.5% of Austria's 260 bathing sites received an "excellent" rating (as of 06/2026, Bundeskanzleramt). That is the fourth-best result among the 29 European countries studied.

Clean water is only half the story. For August, temperature matters more, and it depends on the region. Carinthia and Burgenland keep the water warm for almost the entire summer, while the lakes of Salzburg warm up slightly less.

Below you'll find seven Austrian lakes with the warmest water. For each one, we've listed the region, the maximum summer temperature, who it's for, and what its weak spot is. We checked the water temperatures on 09/12/2026 on the official websites of the state tourism offices.

Lake Wörthersee in summer with mountains and greenery

Which Austrian lakes are the warmest

💡 In short:

The warmest lake in the country is in Carinthia: Klopeiner See.
Wörthersee and Neusiedler See hold at 26-27 °C, but they differ: the first offers resorts, the second offers steppe and wind.
Wallersee, Keutschacher See, and Pressegger See warm up to 24 °C. That's enough for a long swim.
Water temperature and season: 09/2026, checked on the official Carinthia website.

Lake	Region	Summer water temperature	What makes it stand out
Klopeiner See	Carinthia	up to 28 °C (source)	the warmest lake in the country
Wörthersee	Carinthia	up to 27 °C (source)	the resorts of Velden and Pörtschach
Faaker See	Carinthia	up to 26 °C (source)	the only island hotel
Neusiedler See	Burgenland	up to 26 °C (source)	the largest lake in the country
Wallersee	Salzburg	up to 24 °C (source)	beaches and protected shorelines
Keutschacher See	Carinthia	up to 24 °C (source)	campsites and nudist beaches
Pressegger See	Carinthia	up to 24 °C (source)	reed-lined shores and a nature park

1. Klopeiner See

Klopeiner See lies in southern Carinthia, near Völkermarkt and the Slovenian border. It is the warmest swimming lake in Austria: in August the water reaches 28 °C (as of 09/2026, Carinthia tourist office). You swim here in drinking-quality water, and depths in places reach 48 m (as of 09/2026, Carinthia).

The lake has public beaches, boat and SUP rentals, lifeguard stations, and cafes. The shores are gently sloping along most of the lake, so the water warms up quickly and holds its heat for a long time. Six other lakes in southern Carinthia are nearby. In one vacation you can swim in several of them.

Who it's for: families with children and anyone who wants warm water without flying to the sea.
Infrastructure: public beaches, boat and SUP rentals, cafes, and lifeguard stations.

2. Wörthersee

Wörthersee is called the largest lake in Carinthia. The resorts of Velden and Pörtschach sit on its shores, and the water warms up to 27 °C in summer (as of 09/2026, Carinthia). The scenery here is almost Mediterranean, and a bike path about 40 km long runs along the shore (as of 09/2026, tourist office).

From the observation tower above the lake you get a view of turquoise water and the Karawanks mountains. In summer the central beaches are crowded, so arrive at opening time or choose beaches away from Velden.

Who it's for: active travelers: swimming here is easy to combine with bike routes and strolls through the resorts.
Not for: those looking for seclusion and quiet.

3. Faaker See

Faaker See lies in Carinthia, at the foot of the mountains, and warms up to 26 °C (as of 09/2026, Carinthia). The water here is crystal clear and turquoise, and the shores have remained natural. The main feature: in the middle of the lake stands Austria's only island hotel, Inselhotel. The island can only be reached by water.

The region lives by its "Slow Motion" motto: unhurried relaxation, hiking trails, and minimal noise. If you want a peaceful vacation by the water, this is a good choice.

Who it's for: couples and families who value a calm vacation by the water.
Special feature: the Inselhotel island hotel with its own beach on the island.

4. Neusiedler See

Reeds, sailboats and docks at sunrise by the lake

Neusiedler See is called the largest lake in Austria. It lies in Burgenland and extends across the border into Hungary, and the water warms up to 26 °C (as of 09/2026, Neusiedler See region). It is a shallow steppe lake, so it picks up summer heat very quickly.

The shores are surrounded by a national park, and the site itself is on the UNESCO World Heritage list (as of 09/2026, Neusiedler See tourist office). Constant winds have made the lake a center for sailing and kitesurfing. In the reed-lined bays the water warms up faster than in the open water.

Who it's for: families and water sports enthusiasts: sailors, kiters, and windsurfers.
The catch: those same winds kick up waves, so for calm swimming you're better off heading to the mountain lakes on this list.

5. Wallersee

Lake Wallersee among green fields from above

Wallersee is called the largest lake in the Salzburg lake district in the foothills of the Alps. In summer the water warms up to 24 °C (as of 09/2026, SalzburgerLand). It keeps a gentle balance between invigorating and comfortable water, so both adults and children swim here.

Beaches stretch along the shore, and part of the shoreline is strictly protected. Trails for walking and cycling run through the nature reserve areas.

Who it's for: family time by the water with walks along natural shores.
The catch: a significant part of the shore is a nature reserve, so there are fewer wild beaches than at other lakes on the list.

6. Keutschacher See

Turquoise Keutschacher See among forested mountains from above

Keutschacher See hides in the valley of four lakes south of Wörthersee, in Carinthia. The water warms up to 24 °C (as of 09/2026, Carinthia). The lake is surrounded by marshes, wet forests, and meadows, so nature lovers and campers especially appreciate the area.

Popular nudist beaches operate on the southern shores, while families with children swim on the northern ones. If you are traveling with children, choose the northern shore.

Who it's for: camping and a quiet time in nature.
Not for: families who are not comfortable with a nudist beach nearby.

7. Pressegger See

Pressegger See is called the "bathtub of the Gail Valley". In summer the water warms up to 24 °C (as of 09/2026, Carinthia). A dense belt of reeds surrounds the lake.

Families choose these beaches: an amusement park with rides and water slides operates on the shore. The reeds provide shade and shelter the shallows from the wind.

Who it's for: families with children who want to swim and have fun in one place.
The catch: because of the reeds, access to the water is narrower in places than at open lakes.

⁉️🤔 Frequently asked questions

Which lake in Austria is the warmest?

Klopeiner See in Carinthia. It is the warmest swimming lake in the country and is sometimes called the warmest in Europe (as of 09/2026, official Carinthia website). Wörthersee holds second place at 27 °C. At the other lakes on the list, the water warms up to 24-26 °C.

Where can you swim in Austria in August?

In August, warm water holds in Carinthia and Burgenland. Choose Klopeiner See, Wörthersee, or Neusiedler See: the water there does not drop below 24 °C (as of 09/2026, official Carinthia data). The Salzburg lakes are a couple of degrees cooler at this time, but still fine for swimming.

Can you swim in Austrian lakes without risk?

Yes. Water quality is checked throughout the season, and lifeguard stations operate at major beaches.

Which lake is good for a family with children?

Klopeiner See, Pressegger See, and Neusiedler See. Klopeiner See has gently sloping shores and drinking-water-quality water, Pressegger See has an amusement park nearby, and Neusiedler See is shallow and warm. At Keutschacher See, choose the north shore: the south shore has nudist beaches.

How does Wörthersee differ from Neusiedler See?

Wörthersee is a deep mountain lake with the resorts of Velden and Pörtschach, turquoise water, and views of the Karawanks. Neusiedler See is a shallow steppe lake in a national park: the water warms up faster but is murkier, and the wind attracts surfers (as of 09/2026, official regional tourism office). The choice depends on what matters more to you: scenery or water sports.

In short: which lake to choose

If you want the warmest water and the least driving, go with Klopeiner See. For a city-style vacation with strolls through Carinthian resorts, Wörthersee fits well. Steppe wind and water sports await you at Neusiedler See. Quiet time in nature can be found at Wallersee and Keutschacher See, and with children it is convenient to stay at Pressegger See.

Check the water temperature before your trip on the Carinthia website or in the Salzburg Seenbericht.

7 Warmest lakes in Austria: water in summer from 24 to 28 °C