Travel time: Year-round
Interlaken’s climate is defined by its dramatic position between Lake Thun and Lake Brienz, and its role as the gateway to the massive peaks of the Jungfrau region. This geography creates a dynamic and sometimes unpredictable weather environment where valley floor conditions differ sharply from the mountain summits just a few kilometers away.
The most distinctive feature of Interlaken’s weather is the Foehn wind. This is a warm, dry wind that descends from the southern Alps. When it blows, temperatures in the valley can spike suddenly, causing rapid snowmelt in the winter and spring, and clearing the skies to a piercing, high-contrast blue. Beyond the Foehn, the town acts as a meeting point for weather systems coming from both the north and the south, often resulting in localized storms that can be diverted or intensified by the surrounding mountains.
Winters are cold and damp, with high temperatures typically hovering around 3°C to 7°C (37°F to 45°F). Snowfall is frequent and consistent, especially in January and February, turning the town into a white landscape. While the valley floor sees snow, it often experiences "inversion layers" where thick fog sits over the lakes while the mountain peaks remain sunny and warm.
This is a season of rapid transition. March can still feel like winter, while May brings the highest rainfall of the year (averaging 19 rainy days). You might experience "four seasons in one day," starting with morning frost and ending with afternoon sunshine. The melting snow leads to dramatic waterfall flows in nearby Lauterbrunnen, but high-altitude hiking trails typically remain closed due to lingering snowpacks and mud until late May.
Summer is warm and humid, with daytime highs averaging 24°C to 25°C (75°F to 77°F). However, heatwaves are becoming more common, with temperatures occasionally reaching 30°C+ (86°F+). A signature summer phenomenon is the late afternoon thunderstorm. As heat builds in the valley, clouds often gather over the peaks and release sudden, intense downpours before clearing by evening.
September offers some of the most stable and clear weather, making it a favorite for hikers. By mid-October, the temperature drops quickly. November is often the gloomiest month, characterized by shorter days, increasing humidity, and the first significant frosts. This season is less prone to the spontaneous thunderstorms of summer, favoring long-lasting weather patterns.
The weather in Interlaken itself (located at 570m) is significantly different from nearby mountain stations.
Locals rely heavily on Swiss-specific tools like MeteoSwiss rather than global weather apps, which often fail to account for the complex topography. In Interlaken, life doesn't stop for rain; people utilize the "lake-and-cave" strategy—heading to the lakes for cooling in the heat or exploring the St. Beatus Caves and local transport (like the covered paddle steamers) when it rains.
In Interlaken, the humidity is generally high (averaging 75–85% year-round). This means that winter cold feels "sharper" and more biting than dry alpine cold, and summer heat can feel heavy and "tropical" before a storm breaks. However, because the air is exceptionally clean, the sun feels significantly stronger at this altitude than at sea level; the UV index can be very high even on cool, clear days.