I was wondering how the weather is in switzerland in the third week of sept. Is it still warm enough for t shirts and shorts.

Yes, it can be but it also depends on what part of Switzerland you plan to visit.

This post would be better on the Europe board.

Try www.worldclimate.com

Switzerland weather can be very different depending on if you are in the mountains or in a city. I would suggest bringing light pants and short (if you hiking) and both short and long sleeve shirts. A fleece or nice jacket is also a plus. If you are a women, just keep in mind that women typically do not wear short as skirts or capri pants are more popular, especially for dinner.

we are planning to go to grindelwald, murren, and wengen. is there a difference in weather between august and september.
thanks,