Hi there,
I went to Kusidasi, the Onara Hotel end Sep/begining Oct last year. I had a good time, but the beach & swimming in the sea is disappointing. Hotel & food fine, its rightout of town. Having said that there is a Dolumus (local bus) right outside the hotel which goes all over the place for pennies. Several of us went exploring on the dolmus for a fraction of the cost of the trips. Look up on the net where to visit from Kusidasi. I went with the group to Ephesus, stunning, you need a proper guide to tell you what is what. I'd say the weather in Sept/Oct would be miles more shorts/t-shirts than later.
If you go, go & ask to see inside the hotel next door, stunning 5 star plus.
I actually enjoyed the Northern Cyprus holiday more last June.
Helen