Hello Marj
I went in April this year.
It was FANTASTIC! My first Just You and it couldn't have been better :)
We had one morning's rain (so waterproof needed) but it never dropped below 18C and steadily warmed up to over 30C in Xian. I took lightweight trousers, skirts, T shirts of all sleeve lengths and some pretty things for evening, and a cardigan or two. Layers basically! And good shoes for walking/climbing the Wall!
It's a full on holiday , long days but every minute was worth it.
Hope you enjoy yours as much
Debi