One of the first things I have read about Bern is about its Arcades. 6 km of Lauben -as the locals refer to them- boast on of the longest weather-sheltered shopping promenades in Europe. And the first half of our stay I could only admire the geniusness of this invention. The weather in Bern could be nasty but the Arcade system is pretty impressive.
However I really enjoyed Bern when the sun came up and we woke up to snowy, blue sky day. I strongly recommend to go Rosegarten to admire the view of the old town.