Weather in September (Switzerland and Italy)

My personal recommendation is that you pack for everything because there is no answer to your question -- weather is weather. You need to pack for rain - jackets, umbrellas, and potential cool weather along with hot weather. The key is light layers of clothing that can be added or removed as need. I would tend towards typical summer wear - short sleeve shirts, light weight pants but include at least one long sleeve and a light weight wool sweater with a good wind breaker/water proof jacket. If you saw our packing list there are small differences between what we take in the summer compared to winter. For example we will shift to two long sleeve shirts, a medium wool sweater, etc. for winter but again the key is layers of clothes.

Thanks Frank, we did plan on the light weight travlel pants, north face jackets that are waterproof etc... Just was unsure as to more short sleeved shirts to long sleeved shirts. I appreciate your help.

We normal pack three shirts besides what we wear. Summer is two short, one long. Winter is two long and one short. Our rain jacket is a shell but for winter we will add a medium weight fleece vest. The idea is to adjust the layers a little but not add more clothing and more weight.

Your question, basically, can't be answered very well using words. If you go to this website (link below) and spend 5 to 10 mins, you'll get the best answer that's possible:

http://www.wunderground.com/tripplanner/index.asp

When you get to the site, input the location and dates (up to a 2 week time span).

Any other way of answering your question gives you only WAGs, not even SWAGs.

I was in Wengen in September last year and wore a light windbreaker jacket with long sleeved knit tops. I was comfortable even at the high elevations. It was warmer in Italy, and I really got hot in Rome & southern Italy. I plan to take more short sleeved tops for my upcoming trip to Greece in September.

Thank you all for the advice.