September brings cooler mornings and pleasant daytime weather, making it a good shoulder month for both outdoor activities and city visits. Crowds start to thin after August but many summer services still run into the month.
Average daily low and high (°C) and monthly rainfall. The badge shows how it feels, allowing for humidity.
Average temperature across Switzerland in September.
Mittelland
August continues the pattern of warm days and active convective storms, making afternoons humid and prone to sudden downpours; highs generally stay in the mid-20s. This is festival season - expect busy trains and sold-out weekend hotels around Zurich and Lucerne - and the lakes are at their warmest for swimming. Pack insect repellent for evenings and plan outdoor activities for mornings when conditions are most stable.
Geneva, Lausanne, Montreux
September often gives some of the region’s best weather: warm daytime temperatures, crisp nights and reduced humidity ideal for vineyard walks and mountain excursions to Rochers-de-Naye or the Dent de Jaman. Harvest activity in local wineries creates a lively atmosphere, and crowds from high summer thin out. Pack a sweater for evenings and expect some rain as the month progresses.
Interlaken, Jungfrau, Engelberg
September offers quieter conditions and crisp, stable weather windows ideal for multi-day trekking and photography, with clear mountain air and cool nights. Many summer lifts still operate into the month, making alpine access easy; autumn colours begin in higher meadows later in September. Expect lower crowds than July-August; bring warm evenings layers and be prepared for earlier sunset times.
Sion, Zermatt, Saas-Fee, Matterhorn
September offers excellent hiking windows with stable weather, cooler nights and the start of grape harvests in the terraced vineyards. The light is excellent for photography of the Matterhorn and other peaks, and tourist numbers drop after August. Pack warmer layers for early-morning starts and expect some high huts to close by late month.
Lugano, Locarno, Lake Maggiore
September becomes more comfortable as humidity drops and temperatures settle into the low to mid-20s; the weather is excellent for boat cruises and lakeside dining. Locarno’s film festival in late summer can draw crowds but overall the season quiets relative to July-August. Bring light layers for cooler nights and plan water activities for late morning or early afternoon to avoid storms.
Davos, St. Moritz, Chur
September often brings clear, crisp conditions with spectacular autumn colours in wooded slopes and high pastures; nights are cold but daytime windows are very pleasant. Many trails are quieter after the main summer season and accommodation is easier to book, while higher passes start showing the first snows late in the month. Pack warm layers for mornings and expect shorter daylight for long excursions.
An international film festival typically held in late September that draws film industry guests worldwide.
See how September compares with the rest of the year, then read the full guide.