Geneva sits at 375 metres above sea level beside the lake, with a moderately continental climate softened by Lac Léman. Summer is the most popular season — warm, dry, and full of outdoor events — but every season has its own appeal and the city is worth visiting year-round.
Summer (June–August) is the high season. Daytime highs hit 25–28°C, with lakeside cafés, summer concerts, the Fêtes de Genève music festival on the lake in early August (which culminates in one of Europe's biggest fireworks displays), and easy access to the Alps for day-trip hiking. Evenings are pleasant; the lake breeze keeps the heat manageable.
Autumn (September–October) brings cooler temperatures, vineyards in colour, and the Vendanges wine harvest celebrations in the Geneva vineyards just outside town. Crowds are thinner. November is grey and damp.
Winter (December–February) is cold but not extreme — daytime temperatures hover around freezing. The Escalade festival on 11 December commemorates Geneva's 1602 defeat of a Savoyard invasion with torchlit parades, a costumed procession, and the smashing of marzipan cauldrons full of vegetable-shaped chocolates. The surrounding Alps offer some of Europe's best skiing — Chamonix is 90 minutes away by bus, Verbier or Crans-Montana about two hours.
Spring (March–May) sees the city emerge from winter. The flowers in the Jardin Anglais bloom; the surrounding vineyards turn green again. Rain is more frequent than summer but less so than autumn.
For the best balance of weather and crowds, aim for May–June or September.