The weather in Santorini has significant differences throughout the year with high temperatures and almost no rain during the summer (from June to August) and much lower temperatures with cloudy and rainy days during the winter (from December to February). During spring (from March to May) and autumn (from September to November) the weather is usually mild with enough sun and a little rain.
Average monthly temperatures in Santorini
Average monthly rainfall in Santorini
The best time for swimming is from June to September or early October when the sea temperature is higher than 22°C/72°F, while during the summer days there is more than 13 hours of sunshine, on average. However, sometimes swimming is possible in early May too. August is the hottest month, usually without rains, with warm sea but with occasional strong winds, called Meltemi.
Meltemi is a strong north wind which blows in the Aegean Sea mainly in August and usually less throughout the rest of the summer season. Its strongest action is during the afternoon and usually is weaker at night. Sometimes it lasts for days without a break.
Average monthly sea temperature in Santorini
Average daily sunshine hours in Santorini
If you don’t mind swimming, you can visit Santorini from March to May and October to November when the island is less crowded, prices are lower and you can explore Santorini with pleasant temperatures and little or even no rain during your visit.
The winter period is the low season, but still an increasing number of hotels and restaurants stay open as recently the touristic period is getting gradually extended. The prices are the lowest of the year, you can find some really good deals and enjoy the tranquility of the island.