Weather in Santorini in May

How May compares

May is the 6th warmest month of the year in Santorini and ranks 124th of 134 destinations we compare for May - see where else is hot in May. Within Greece it is 41st of 44 (Greece in May). Against London's average high of 16.6°C in May, Santorini is 3.0°C warmer by day and 7.8°C warmer at night.

Daytime and night-time in May

The typical May day in Santorini peaks at 19.6°C, but that is an average: the warmest 10% of days reach 22.0°C or more. Roughly 1 in 59 days top 25°C. Nights average 16.1°C; one night in ten drops to 13.9°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest May day here reached 29.5°C (2020-05-16) and the coldest night 11.4°C (1991-05-03).

Rain in May

Dry (3 rainy days or fewer): about 2 days with 1 mm or more, 10 mm in total. Year to year it varies a lot - the wettest May was 2007 with 54 mm, the driest 1995 with 0 mm. Humidity averages 74%.

Sea temperature in May

The sea averages 18.9°C - bracing (18-22°c). Depending on the year it ranges from 18.2°C to 19.7°C. For the warmest sea here, come in August (24.6°C).

Sunshine and daylight

Around 10.6 hours of sunshine a day (estimated from cloud cover), 13.9 hours of daylight: the sun rises about 06:11 and sets about 20:18 local time in mid-May. Average cloud cover is 24%.

Is May a good time to visit Santorini?

It is a reasonable choice: mild days. The best months for Santorini on our scoring are July, August, September; months averaging 25°C or more: Jul, Aug.

Comfortable days, but pack for cooler evenings

Think light layers rather than a suitcase packed only for summer. A T-shirt may suit the warmer daytime spells, but bring a jumper or light jacket for evenings and cooler days. Even the warmest days typically offer gentle warmth: the warmest 10% reach 22°C or more, while only 2% reach 25°C. That makes May a sensible choice if you dislike heat at midday, but a less convincing option if strong warmth is the point of your trip. The colder nights can fall to 13.9°C or below, so long trousers and an extra layer are useful for sitting outside after dark.

Plenty of sunshine, with a cooler sea

Rain is unlikely to dominate your plans, with about 2 rainy days across May. You can reasonably plan around being outdoors, while keeping some flexibility rather than expecting an entirely dry stay. There are about 10.6 hours of sunshine within 13.9 hours of daylight, giving you plenty of scope to spread outdoor time across the day. Sun protection still belongs in your bag even when the air feels mild. Swimming is the bigger compromise: the sea remains bracing, so brief dips may appeal more than lingering in the water. If comfortably warm sea swimming matters more than dry weather and daylight, May is not the strongest fit.