In the past evenings used to be pretty chilly in May (several layers and hoodie) and October similar.
My observation having lived here 15 years is that now from April through to the end of October there is rarely a need for a jacket in the evenings, even up the mountain in Ovacık.
I wouldn't worry too much.
Bring clothes for the sunny warm days and maybe a couple of light trousers or jeans and a couple of cardis or pashminas for the evening or when you are sat in the shade in the day if there's a breeze, which there often is in the afternoons in Çalış.