informational 8 min read
The Best Time for a Boat Trip in Santorini
Updated October 27, 2026
For a day on the water, the best months are June and September, with late May close behind. The sea is 19 to 24°C, it hardly rains, and the meltemi wind is not at its July and August peak. July and August have the warmest sea, but also the strongest afternoon wind. From November to March many boats stop until spring.
The year in numbers
Air temperature and rain days are 1991–2020 climate normals from Open-Meteo for a grid point over the caldera. Sea temperature is the monthly average from weather2travel. Sunset is computed for the 15th of each month, in Greek local time.
| Month | Air high °C | Air low °C | Rain days | Sea °C | Sunset |
|---|---|---|---|---|---|
| January | 12.9 | 10.0 | 11 | 16 | 17:25 |
| February | 12.9 | 10.0 | 11 | 16 | 17:58 |
| March | 14.0 | 10.9 | 9 | 16 | 18:24 |
| April | 16.2 | 13.0 | 4 | 16 | 19:51 |
| May | 19.6 | 16.3 | 2 | 19 | 20:17 |
| June | 23.3 | 20.1 | 1 | 22 | 20:37 |
| July | 25.3 | 22.2 | 0 | 23 | 20:36 |
| August | 25.5 | 22.6 | 0 | 24 | 20:10 |
| September | 23.6 | 20.9 | 2 | 24 | 19:27 |
| October | 20.8 | 18.1 | 5 | 22 | 18:43 |
| November | 17.4 | 14.7 | 11 | 19 | 17:10 |
| December | 14.4 | 11.7 | 12 | 17 | 17:04 |
The model’s grid point sits over water, so its afternoon highs run low. weather2travel puts the average daytime high at 28°C in July, for example. The pattern still holds either way: rain falls almost entirely from November to March, and June to September is dry.
Sea temperature: when swimming stops feeling cold
Every catamaran in our list stops for swimming, so the sea matters as much as the air. It sits at 16°C from January to April. It reaches 19°C in May and 22°C in June. It peaks at 24°C in August and September, then falls back to 22°C in October and 19°C in November. WeatherSpark puts the warm-water season, above 23°C (73°F), at 25 June to 6 October.
The hot springs do not fix a cold sea. The listings describe them as up to about 4°C warmer than the open sea, not as a heated pool. One October reviewer of the volcano cruise wrote that the springs were “not warm during our trip in October – very cold”.
The meltemi
The meltemi, also called the etesian wind, is the dry northerly wind of the Aegean summer. It blows from about mid-May to mid-September and is strongest in the afternoon. It can reach force 7 to 8 on the Beaufort scale, and it can arrive in clear weather with little warning. Sailing guides put its peak in July and August.
Averaged over the whole day, Santorini is actually windier in winter. WeatherSpark’s windiest month is February, at 16.0 mph, and its calmest is May, at 11.2 mph. July averages 13 to 15 mph. The summer problem is the afternoon gusts, which arrive just as the day and sunset cruises are out.
What a strong meltemi does to your trip is spelled out on the listings and in reviews:
- Stops change. The sunset, luxury and small-group catamaran listings all say the route and stops may change without notice in bad weather.
- Boats change. The wooden boat listing reserves the right to switch to another vessel. Two August reviewers booked the wooden boat and sailed on a catamaran.
- The deck gets cold. One October small-group reviewer described high wind, strong currents and a “very chilly” evening under the covered area.
The wind page covers cancellations and refunds.
Month by month, for a boat trip
April. The sea is still 16°C and there are about 4 rain days. Fine for a scenic cruise, cold for swimming.
May. 19°C sea, 2 rain days, and WeatherSpark’s calmest month. Late May is a good compromise.
June. 22°C sea, 1 rain day, and the latest sunset of the year at 20:37. The meltemi has started but is not yet at its peak.
July and August. The warmest sea, at 23 to 24°C, and no rain. They are also the meltemi peak, and they sit in the government’s peak season for cruise calls. Book a morning cruise if wind worries you, since the meltemi builds in the afternoon.
September. 24°C sea, 2 rain days, and the meltemi easing from mid-month. Sunset is back to 19:27, so sunset cruises leave earlier.
October. 22°C sea and 5 rain days. Fewer boats run as the month goes on, and reviews start to mention cold water.
November to March. 11 to 12 rain days in the wettest months and a 16 to 19°C sea. Many of the cruises we list do not take bookings until March or later.
Crowds and holidays
No source publishes daily visitor numbers for Santorini, so we will not invent a crowd calendar. Greece’s own cruise-passenger fee gives a guide, though. The government charges its highest rate, €20 per passenger, from June to September, and a mid rate in April, May and October.
The Greek public holidays to plan around are Easter (12 April 2026 and 2 May 2027), Assumption Day on 15 August, and Ochi Day on 28 October.
The short answer
For swimming, snorkelling and a sunset on deck, choose June or September. For the warmest water and long evenings, choose July or August, and book a morning cruise if wind is a worry. In April, May or October, pick a cruise for the views rather than the swim stops, and pack a warm layer.
Frequently asked questions
What is the best month for a boat trip in Santorini?
June and September. The sea is 22 to 24°C, rain is close to zero, and the meltemi is not yet, or no longer, at its July and August peak. Late May works if you can take cooler water at 19°C.
Is Santorini windy in August?
Often, in the afternoon. The meltemi blows from about mid-May to mid-September, peaks in July and August, and can reach force 7 to 8. Boats change their route or swim stops when it blows.
Can you swim in Santorini in October?
Yes, the sea averages about 22°C. Several October reviewers still called the water and the hot springs cold, so expect it to feel fresh.
Do boat trips run in winter?
A few do. On 27 October 2026 the day catamaran, sailing catamaran and wooden boat still had dates that week. The sunset catamaran's next date was 15 March 2027.
Sources