Honest guide
Lauterbrunnen sits on the floor of a deep, steep-sided valley at 800 m. That makes it spectacular, and it means fog, low cloud and short winter daylight are real. Here is the honest version the brochures skip.
Yes. This is the thing the postcards never mention: because the valley is narrow and deep, low cloud and fog can settle on the valley floor, especially in late autumn and winter, and the high walls mean the sun reaches the bottom for only a few hours even on a clear midwinter day. Some visitors find the valley atmospheric in that mood; others find it gloomy. Both reactions are fair.
The single most useful thing to know is that the weather on the valley floor and the weather up top are often completely different. When Lauterbrunnen is grey and damp, Wengen, Mürren and the high pistes are frequently above the cloud in full sun. Check the mountain webcams in the morning; if the valley is socked in, ride up rather than writing the day off. That one habit rescues most “bad weather” days here.
Layers and a waterproof, whatever the month. The valley can be cold and damp while the slopes above are bright and mild; you want to be ready for both in the same day.
Common questions
No, but the deep valley does get fog and low cloud, especially in late autumn and winter. It is often clear and sunny up the mountain even when the valley floor is grey, so heading up usually beats the murk.
The valley is narrow with very high walls, so the low winter sun reaches the valley floor for only a few hours. Going up to Wengen or Mürren gets you into the sunshine.
Autumn (September–October) is often the most stable and clear, with fewer crowds. Summer is warmest but prone to afternoon storms; winter is cold with reliable snow up high.
When the valley floor is grey, ride up to the sun, then come back to the private hot tub in The Apartment. A short walk from the village.