More ideas from Siv
Travelista Packing Essentials for Summer.  Josie further suggests, if packing for a wide temperature range:  "The down vest I usually wore over a long sleeve tee on cold mornings and then just stuffed it in my purse when temps warmed up. If it got really cold I’d layer my vest over my jacket and I’d be fine."

Travelista Packing Essentials for Summer. Josie further suggests, if packing for a wide temperature range: if use a denim jacket and white long sleeve