The warmest weather in Santorini is between June and September when it’s sunny, hot, and the water is perfect for swimming. The climate of Santorini is typically Mediterranean, with mild winters and warm and sunny summers.
July is the hottest month in Santorini with an average temperature of 26°C (79°F) and the coldest is January at12°C (54°F) with the most daily sunshine hours at 14 in July.
In the summer months daily sunshine is quite predictable. Sun worshippers can count on about 13 hours of sunlight during June, July and August. April through May averages about 10 hours of sunshine daily, with less than four to six hours in the winter months.
Locals can assure you that there won’t be any precipitation during summertime and especially from May to September. If you experience summer rain in Santorini, then something serious must be going on with the planet climate.