Jun 23, 2014 - 4:39 AM
2. Summer is the most rainy season on average, but in most cases that's only at the end of the day. Anything is possible: weeks can go by with almost no rain or it can rain for a week. Mostly, the weather is really nice though. You really only know on the day itself.
For tips on how to best plan the trips, please see the pages of the specific attractions, e.g. Jungfraujoch, Gornergrat, etc.
3. See our city pages and their "What to do" section for ideas: Geneva, Bern, Interlaken, Lucerne. Interlaken isn't really a sightseeing town as there's no much to see. It's the surrounding area that makes it special. There are two nearby lakes, Lake Brienz and Lake Thun. Links to the timetables can be found on these pages. There are boat services in the early evening as well.
A Swiss Pass allows you to use the trams in Bern for free, although you can easily walk if you just want to see the historical town center.