Holiday Destination - Not too hot!

In the process of organising summer hols. We are lookin for a location where temperatures are not too high i.e. about 20-22degrees at the end of june/early july - cool enough to be able to get out and about and do a bit of exploring in the area. We have 2kiddies in tow (ages10+13) so we want to be close enough to a city for acitivities/choice of places to eat in evenings, etc. We are currently looking at the S/W of France but just want to check what other countries are available to us. Any recommendations much appreciated.

We went to Austria last year - as not a fan of the hot weather myself. Did 3 nights in Salzburg - then a week in Zell am See , then three nights in Vienna.

Was a great holiday. We had an 18 month old with us - and there was lots to do and see.

Was in Jersey a few years ago with aged parent. Generally in the low 20s. a beautiful place for walks.