What clothes do I need to wear to go to the Swiss Snow Mountain?

1) There is no down jacket to rent or lend, because many foreigners wear shorts and a coat, and they grow up in good health.

2) Wearing down jackets is not so exaggerated. It's still quite hot at the foot of the mountain in August, and it's a little cold at the top of the mountain, but pants (such as jeans or long pants)+spring and autumn coat (or coat+fleece shirt) is enough. At the top of the mountain, you don't get off the train or go outdoors. The train stops in the cave and leads to the indoor viewing room. It's heated. You can go outside to see the snow and mountains through the tunnel, take pictures and come back when it's cold.

It is enough to go to Jungfrau in August and put on shorts and shirts (see background figure);

The viewing room on Jungfrau is still relatively warm, which means that you need pants+coat outdoors, but not to the extent of down jacket: