Three networks cover Santorini - Cosmote, Vodafone and Nova - and your eSIM will use whichever reaches the cliff you are standing on. Greece is in the EU, so roaming carries no surcharge, and coverage across this island is better than its geography suggests. Our Crete, Rhodes, Kos and Zakynthos guides handle the Greek islands' usual questions. Santorini's own are different, and two of them are recent: the ground moved a great deal in early 2025, and the rules about who may come ashore have changed since.
Worth understanding properly, because the coverage at the time was alarming and the reality is more specific.
Between late January and February 2025 the sea between Santorini and Amorgos produced an extraordinary earthquake swarm - over 1,200 tremors in a fortnight, with more than a hundred above magnitude 4 and the strongest around 5.3.
Around 9,000 people left, out of a resident population of roughly 15,500. Schools closed, a state of emergency was declared and the season was disrupted.
It was not the volcano erupting. Subsequent research traced the cause to a body of magma - on the order of 300 million cubic metres - intruding as a sheet through the crust between the islands, which triggered tectonic seismicity rather than a surface eruption.
The swarm subsided. The island returned to normal, the season resumed, and it has been quiet since.
Santorini is an active volcanic system and always has been. Nea Kameni, the black island in the middle of the caldera, is the current vent, and it is monitored more closely now than at any time in its history.
Greece broadcasts emergency alerts by cell - the 112 system reaches every handset on a Greek network, including roaming foreign ones, and it was used during the swarm. Leave your emergency alerts enabled.
None of this is a reason not to come. It is a reason to know what the island is, and to know that if your phone makes a noise you have never heard before, you should read it.
Santorini has become one of the standard examples of overtourism, and Greece has started charging for it.
A cruise passenger levy applies here. Since July 2025, passengers stepping ashore at Santorini and Mykonos pay a tiered fee - 20 euros per person in the peak months of June to September, 12 euros in April, May and October, and 4 euros from November to March. Other Greek ports charge considerably less.
Cruise lines absorb it into the fare rather than collecting at the gangway, so you may never see it itemised.
Caps on cruise arrivals have followed, limiting the number of passengers landing on a given day.
Why it matters to you: on a heavy cruise day, Oia and Fira are genuinely unpleasant between about ten and five. On a light day they are merely busy.
The practical trick is to be in the villages early and late and somewhere else in the middle of the day, and to check how many ships are scheduled - the port calendars are public.
Or come outside the peak. May and October give you the same island with a fraction of the pressure and a much lower levy, which is precisely the intention.
Fira, Oia and the caldera rim are well covered, and the network handles the summer population reasonably well.
Down in the caldera - on a boat, or on the path to the old port - signal shadows form under the cliffs, which are up to 300 metres high.
Nea Kameni, the volcanic islet, is patchy on the crater walk.
The Fira to Oia cliff path, a three-hour walk and one of the best things to do here, drops in and out along the exposed sections.
On ferries, coverage fades in the middle of the crossing to Ios, Naxos or Crete.
Congestion is the summer failure. At sunset in Oia, several thousand people in a few hundred metres all trying to upload at once produces full bars and nothing moving.
Two practicalities that shape a stay more than people expect.
The villages are built down a cliff. Hotels advertise caldera views because the rooms are cut into the rim, and reaching them means steps - often a hundred or more, with luggage, and no lift.
Check the stair count before booking if anyone in your party has mobility issues. Some properties are reached only on foot down a stepped lane.
The donkeys are a live welfare issue. Riding them up the old port steps has been widely criticised, regulations have tightened, and the cable car exists. Most visitors now walk or ride the cable car, and that is the right call.
There is no fresh water on Santorini. The island has no rivers and negligible rainfall, and its supply is desalinated. Tap water is generally not drunk - bottled is the norm - and water use is a genuine constraint on the island's capacity.
Which is also why the wine works. Assyrtiko vines are trained into low woven baskets on the ground, protecting the fruit from the wind and catching what moisture the sea air provides. The wine is excellent, bone dry and unlike anything else in Greece.
- A ferry app or the operator sites, for Blue Star and the fast catamarans - and check them daily in summer, for the reason below.
- Maps, with offline copies if you are walking the cliff path or driving the south of the island.
- A cruise port schedule, which tells you which days to avoid Oia.
- A weather and wind app. The meltemi, the strong northerly that blows through July and August, routinely cancels fast ferries even in perfect sunshine.
- A translation app is optional. English is universal in tourism here.
Santorini (JTR) is a small airport on the east side that handles a very large seasonal load, and it feels it. Allow time on departure.
Athinios is the ferry port, at the base of the caldera cliff, reached by a road of steep switchbacks. Arrivals there are chaotic - buses, transfers and taxis compete for the same space - so pre-book a transfer if you can.
Ferries from Piraeus take five to eight hours on the conventional boats and around five on the fast ones, and connect to Ios, Naxos, Paros and Crete.
The meltemi cancels sailings. In July and August, a fast ferry can be cancelled on a cloudless day because of wind. Never plan to catch a flight home the same day as a ferry crossing.
Buses run between Fira and the main villages and are cheap and crowded; ATVs and small cars are widely rented, and parking in Oia and Fira is the constraint rather than the driving.
Little. Wifi is everywhere, the island is small, and EU visitors are on their home allowance. What earns its keep is checking ferry status and cruise schedules, both of which you will do more often than you expect.
Proper shoes for the stairs and the cliff path - the single most useful item here. The paths are stone, uneven and polished by use.
Light clothing in summer, with something windproof for the meltemi, which is strong enough to be genuinely tiring.
A layer for evenings, which cool quickly once the sun goes behind the rim.
Swimwear and reef shoes - the beaches are black volcanic sand and pebble, and they get very hot underfoot.
Something smarter for dinner. Santorini dresses up, and the caldera-view restaurants are dressed occasions.
Sun protection, seriously - there is almost no shade anywhere on the rim.
Oia's blue domes, from the walkway above them, in the first hour after sunrise when you will have them to yourself.
Sunset from Oia castle, which is the famous one and involves standing in a crowd for an hour beforehand. The walk back down Fira's rim at the same hour is nearly as good and almost empty.
The caldera from the Fira to Oia path, roughly two thirds of the way along.
Nea Kameni's crater, from the volcano walk, with the island ringed behind it.
Akrotiri, the Bronze Age town buried in ash and excavated under a modern roof - frescoes, drainage, three-storey buildings, all around 3,600 years old.
Red Beach and the southern coast, for the colour of the cliffs.
A winery at Santo or Venetsanos, with the vines in their baskets and the caldera below.
Amoudi Bay, at the bottom of Oia's steps, for the fishing tavernas and the swim off the rocks.
The Minoan eruption here was one of the largest in human history. Around 1600 BC the volcano removed the centre of the island and left the caldera you are looking at. The tsunami and ashfall are widely thought to have contributed to the decline of Minoan Crete.
Akrotiri was buried and preserved by that eruption, which is why it is sometimes called the Minoan Pompeii - except that no bodies have been found, suggesting the town was evacuated in time.
Plato's Atlantis is often traced to this event, which is unprovable and irresistible.
The caldera is flooded - the water inside it is up to 400 metres deep, which is why cruise ships anchor rather than dock.
Santorini has no fresh water of its own and runs entirely on desalination.
And the island's proper name is Thira. Santorini comes from Santa Irini, a name given by Venetian sailors.
The season, roughly May to October, with July and August the peak in every sense - heat, crowds, prices and wind.
Ifestia, the volcano festival in late summer, with a fireworks re-enactment of an eruption over the caldera.
Greek Orthodox Easter, which in the villages here is genuinely local and quite different from the summer island.
The grape harvest, in August, unusually early because of the heat.
May and October are the best months: warm enough to swim, far fewer ships, and the lowest cruise levy tier.
The love: the caldera is one of the great sights on earth, and no photograph prepares you for standing on the rim. Akrotiri is a genuinely world-class archaeological site that most visitors skip. The wine is distinctive and very good, the food has improved enormously, the sunsets deserve their reputation, and the villages, early in the morning before the ships arrive, are as beautiful as anywhere in the Mediterranean.
The complaints are consistent and largely fair. The crowding in peak season is severe enough to ruin the experience. It is expensive, the priciest of the Greek islands by a distance. The stairs defeat some visitors entirely. The beaches are ordinary, black sand and pebble, and people who came for beaches are disappointed. The sunset scrum in Oia is genuinely unpleasant. And the island is small - two or three days covers it, and many stay longer than it repays.
Come in May or October, be in the villages at dawn, check the ship schedule before planning a day, and give Akrotiri a morning.
The swarm ran from late January into February 2025 - over 1,200 tremors, the strongest around magnitude 5.3 - and prompted around 9,000 residents to leave temporarily. It was caused by magma intruding as a sheet through the crust rather than by an eruption, and it subsided. The island is back to normal and is monitored more intensively than ever. Greece's 112 system broadcasts emergency alerts to all phones including roaming ones, so leave those alerts enabled.
Yes. Since July 2025 a tiered levy applies at Santorini and Mykonos - 20 euros a head from June to September, 12 in April, May and October, and 4 in winter. Lines generally absorb it into the fare. Caps on daily cruise arrivals have followed, and both measures exist because peak-season crowding here had become unmanageable.
Check daily in summer. The meltemi, a strong northerly that blows through July and August, cancels fast ferries regularly on otherwise perfect days. Never book a ferry and a flight home on the same day.
Under the caldera cliffs - on boats, on the path to the old port, and along exposed stretches of the Fira to Oia walk. The rim villages themselves are well covered, though at sunset in Oia the network saturates and you get full bars with nothing moving.
