We are leaving for Germany and Austria tomorrow! I'm so excited I can barely stand it. After packing for warm weather, my neighbor just informed me Frankfurt/Munich area is in the 70's right now and cooler in the evenings. (Her mother lives in Munich) YIKES! Now I am having to repack some warmer things. Any suggestions on clothing?
Last July I was on the Berlin, Prague and Vienna tour. The temps ranged from the 60's to the 100's plus. So, don't leave those warm weather clothes behind. You need to think layers as everyone on this site preaches. Throw in a sweater or a fleece and you'll be fine. You should be taking some sort of rain jacket which will be another layer. If you have a long sleeved shirt you'll be fine. If worse comes to worst you can always get a sweater as a souvenir.
It is so hot in Frankfurt right now. I think it was 90 or so yesterday. Keep those clothes for warm weather in your suitcase, but yes, bring a light jacket or raincoat with you too. Have fun in Germany!