Autumn - Kyoto, Hiroshima, Kobe, Nagoya

Hi, I am planning to head to Japan during the autumn season and would like to know when are the best dates to travel to the following areas:
Kyoto & Arashimaya
Kobe (will there be any koyo spots? or should I just visit the town as it is?)
Nagoya (Korankei valley in particular)
Hiroshima (any koyo spots?)

Much thanks!

It seems you're looking for this page: http://www.japan-guide.com/e/e2014.html

Here's a list of places for a to visit in Hiroshima if you have the time.

http://gethiroshima.com/features/autumn-colors-guide/

I'll recommend Sandankyo gorge if you're looking for something off the beaten track. The more popular place (meaning lots of tourists) would be Miyajima, especially with Itsukushima shrine there as the main attraction.