Bergen has a reputation for rain — and it is well-earned. The city receives around 2,200 mm of rain per year, making it one of the wettest cities in Europe. No month is reliably dry. That said, the weather varies enormously from day to day, and even in July you might get a week of sunshine or a week of grey drizzle.
Summer (June–August) is the main tourist season. Days are very long — in June, it barely gets dark. The fjord excursions are in full swing, the fish market is at its most lively, and the light on the Bryggen facades in the evening is beautiful. The downside is crowds and price — Bergen gets a lot of cruise ship traffic, and the area around Bryggen can feel overwhelmed on busy days.
May and September are the best compromise months: fewer tourists, lower prices, the same scenery, and a reasonable chance of decent weather. The hills around the city are at their most dramatic in autumn, when the birch trees turn yellow against the dark rock.
Winter (December–March) is wet and dark but has its advocates — the Christmas markets are pleasant, the museums are quiet, and the city functions normally. Bergen is not an ice-and-snow destination; the west coast climate is too maritime for reliable winter conditions.
The Bergen International Festival (late May/early June) is the main cultural event — a two-week programme of music, dance, and theatre that takes over the city.