Wengen has two distinct high seasons. The ski season runs roughly mid-December to mid-April; snow on the upper slopes is usually reliable from January. The Lauberhorn race in mid-January is the busiest week of the year — book accommodation many months ahead or avoid the date entirely.
Summer hiking season runs from late June, once the high meadows are clear of snow, to mid-September. July and August are warm and busy; June and September are quieter, with wildflowers in early summer and clearer air in autumn. October to early December is shoulder season — many hotels and lifts close, the village is half-asleep, but the weather can be glorious. May is the lowest point: too late for skiing, too early for hiking, much of the lift network shut.