Weather

That's a bit of a vague question. Where in Switzerland? Where in Italy? The weather varies a LOT depending on north/south and high altitude/low altitude. Look at wunderground.com for historical information but you will need to specify towns/cities.

I use this: http://www.weatherbase.com/

Thank you ;) Just another question
In switzerland if I buy 2nd class Swiss pass do I need to reserve the seats ?

Reservations for trains in Switzerland aren't necessary. The beauty of the Swiss Pass is that you can hop on an off inter-city trains without needing to bother with ticket windows.

I will b traveling Milan-rome ( and back ) Milan-venice(and back) Is there like a saver pass like Swiss pass ?
Or do I need to buy fast train back n forth

Sanny there is a Italian railpass, but not worth it for your trips. I would buy round trip tickets for your two trips from/to Milan. You will probably need seat reservations for the fast trains anyway, and it is easier if you buy them when you buy the tickets.