August in Switzerland is peak summer: warm lakes, open mountain lifts, long hiking days, busy alpine villages, and that dreamy feeling that everyone in Europe has collectively decided to be outside. But August is not guaranteed blue sky weather, especially in the Alps. You can get gorgeous sunny mornings, hot city afternoons, cool mountain air, and sudden summer rain or thunderstorms all in the same day. The good news is that rain doesn’t have to ruin a Switzerland trip. In August, it often just means shifting the day toward waterfalls, gorges, panoramic trains, chocolate, cheese, spas, castles, or a very strategic pastry stop.
Lower / Non Mountain Regions
Region
Typical August temp swing
Typical August rain pattern
Zurich
About 14–24°C / 58–75°F
Warm summer city weather, but still around 12 wet days and about 119 mm / 4.7 in average August rain.
Lucerne
About 14–24°C / 58–76°F
Wetter than Zurich, with about 13 wet days and 170 mm / 6.7 in average August rain.
Central Switzerland / Bernese Oberland foothills
Low towns: 14–24°C / 57–75°F; higher places like Engelberg: around 11–21°C / 51–69°F
This area can be notably wet in August: Interlaken averages about 146 mm, Engelberg about 196 mm, and Pilatus about 161 mm.
Geneva
About 14–26°C / 58–79°F
One of the warmer lowland cities; averages about 81 mm / 3.2 in over 8 wet days in August.
Montreux
Roughly 13–26°C / 56–78°F
Lake Geneva microclimate; generally warm, with rain patterns similar to the Lausanne/Nyon side of the lake.
Lausanne
About 16–25°C / 61–76°F
Warm but not dry; averages about 110 mm / 4.3 in over 10 wet days in August.
Mountain / High Elevation Regions
Region / Town
Typical August temp swing
Rain / storm pattern
Interlaken
Around 12–24°C / 54–75°F
Warm valley/lake town, but still rainy by Swiss summer standards. August averages around 146 mm / 5.7 in of rain, and some climate summaries estimate rain on roughly 45% of days.
Lauterbrunnen
Around 9–18°C / 48–65°F
Cooler than Interlaken because you’re deeper in the valley, with lots of waterfall/mountain moisture. Historical summaries put August around 18°C / 65°F highs and 9°C / 48°F lows.
Wengen
Roughly 8–18°C / 46–64°F
Similar to Lauterbrunnen but higher, so mornings/evenings feel cooler and clouds can sit right on the village.
Mürren
Roughly 7–17°C / 45–63°F
Higher, cooler, and very weather-dependent. It can feel incredible in clear weather and socked-in during cloud/rain.
Grindelwald
Around 9–18°C / 48–65°F
Similar to Lauterbrunnen: cool alpine summer weather, humid, with showers or thunderstorms possible. August summaries put Grindelwald around 18°C / 65°F highs and 9°C / 48°F lows.
Jungfraujoch / high mountain excursions
Often around 0–10°C / 32–50°F in August
This is a different world from the villages. Even in August, bring layers, wind protection, and sunglasses/sunscreen if it clears.
Zermatt
Around 8–20°C / 47–67°F
Drier than many Bernese Oberland mountain towns, but storms and poor visibility still happen.
St. Moritz / Upper Engadine
Around 5–19°C / 40–66°F
Cooler, high-elevation, and often crisp. Nearby Samedan normals are much cooler than the lowland cities.
