January 2018 was an unusually warm and wet month across the Western Alps, with widespread landslides at low elevations and massive snowfall higher up. This extreme month yields lessons for how mountain communities can prepare for a warmer future. The weather of January 2018 was unusual — at the upper extreme of the historical distribution of storminess, temperature and precipitation measurements in the Western Alps — and broke many weather records. Not only was January 2018 unprecedentedly warm, it was also extremely wet, with unusual snowfall at higher elevations. As regional climate models predict substantial warming and, to a lesser extent, increased precipitation1 across the European Alps, we argue that the extreme weather conditions and associate mass wasting observed during January 2018 could yield valuable insights into typical winter conditions to be expected by the end of the twenty-first century.