Hi Merce, I went to the Cilento Coast a few years ago in October - it was the last trip out of the year. I don't like hot weather so always try for the cooler dates. For me the weather was great, a bit muggy occasionally, but usually warm rather than hot.
The spa wasn't open when I went, would love to go back. It's a really nice laid back trip, excursions to go on every day if you want to go on them. A quiet part of Italy and super hotel. A good choice for a first JY trip.
Katy