what will the weather be in mid may 2012
I live in the west part of Switzerland but the weather in Bad Ragaz shouldn't be much different.
In may you can get anything from rain and 10 degrees celsius to beautiful blue sky and sunshine and 27 degrees.
In mid-may it's often nice and sunny with 20 to 25 degrees but there's no guarantee...
At night time it always gets colder, I would say 5 to 15 degrees.
I would take summerish clothes but also a sweater and a coat.
I disagree -- I live in South West Switzerland and the weather patterns are often quite different in the North- East of Switzerland. Bad Ragaz is about as far East as one can go - not quite, but almost.. And further north than Bulle.
You need to specifically check the weather forecast for Bad Ragaz about a week before you get there. It is one the border between the canton of St Gall and the Graubunden...
The above post is correct however in that you will need to think about "layered" clothes. It can also snow anywhere in the mountains at any time of the year...