depends how warm/cold you are in this country.

I went to Kos mid september last year and there was no way i was wearing anymore than a t-shirt or short sleeved shirt in the evening. but then there were women with small cardigans on.

End of the day its how warm you are in general

I'm going to Kos later in August and I better not need any wooleys!!!!

According to the BBC weather the minimum night time temperature this week is 22-25 so I wouldnt be packing too many thermals!

we have been in october last two years, and all i wore at night is a shirt and shorts, too warm for me for long trousers,so i think you can leave the thermals at home,all tho same as gaffer says some women like to wear a small cardigan, depends what age group you are i suppose, dont think you will tho in august,
jeppo

I was in Greece on the mainland last Sept. I did take a couple of long sleeve tops but didn't need them until I arrived back in Manchester.

I was in Kos last September and wore a little cardi around 10pm when it got a bit cooler. It's always better to pack one, just in case.

I just usually wear short sleeved tops and dresses and carry my pashmina incase I get a little chilly.