Snow!
I remember one family summer holiday in Bavaria. It was glorious week of Teeshirts, shorts and sandals as we drove through the mountains to Berchtesgarten where we unexpectedly met many of our daughters' School Teachers at the Lift to the Eagles Nest.
On stepping out of the Lift and walking through the Cafe area on to the Patio, we found we were stood (in Shorts and Sandals) in 6 feet of Snow!