Choose early autumn as the best time to visit Santorini when the crowds are scarce. Beach season on the island runs from May through late October, but August is the busiest. September and October bring relief from crowds and perfect mild weather. Climate cools a little in autumn, and this is when the Ifestia Festival takes place. Money saving will be possible in low season from November through March.
The period from April to May is a good time for sightseeing and hiking. You can also try donkey ride and taste outstanding Santorini white aubergines and cherry tomatoes with the beginning of summer. And don't forget about breathtaking Santorini sunsets anytime except winter months.