I took the Turkey trip in October a few years ago and it was wonderful. Temps generally in the high 70s, warm enough to swim in the Med in Antalya and a bit cooler in Capp. I brought a fleece jacket and wore it only for the early morning balloon ride. We had only one day of light rain on the way to Ankara so wore a rain jacket that day. It was very warm at Ephesus you'll need a hat for sun protection.
It's a great trip, consider taking the balloon ride, it was amazing.