Is Santorini in August too hot? It’s 30 to 33°C (86 to 91.4 °F) in the sun, higher in a heatwave, and 2026 is running hot across Greece, today’s rainstorm aside. And yet, the island gives you three tools the weather sites don’t mention. There’s the meltemi wind that moves through the villages, the cold underground rooms this island has always built, and a daily clock that locals follow instinctively. You don’t fight August heat here, you schedule around it. Below is how I’d build your day in August—the same way I plan my own.
What the weather actually does in August
The average high is around 27°C (81°F). The average low is about 22°C (72°F). The sea sits at roughly 25°C (77°F), its warmest of the year. Rain falls on about never—August and July are the driest months here. You get eleven to twelve hours of sunshine a day, and a UV index around 9, which is in the “very high” band.
On the hottest days it reaches 33°C (91°F) or more, and heatwave spikes go past that.
Now the part the averages hide
An average high of 27°C (81°F) sounds mild, but that isn’t what your body reports at two in the afternoon in Fira. Santorini’s villages are built of white plaster and stone that hold and throw back heat all day. Besides, there’s very little shade on the caldera paths and no grass anywhere to cool the air.
That gap is why people arrive prepared for 27°C and find themselves immediately sitting down in the first bar with a view. Believe me, the Greek ‘siesta’ is there for a reason.
The sons of Boreus are real, and they have favorite villages
The meltemi—the dry northern wind that rules the Aegean all summer—is why Santorini sits at 30°C (90s°F) while Athens passes 40°C (104°F). It’s pretty uneven: some lanes channel it, while others block it. Meaning that a terrace that’s brutal at noon can be comfortable at six because of how the village was built to catch or repel the currents.
Cycladic villages were engineered around the sun and wind centuries before anyone said the word ‘microclimate’. Whenever I walk around one, the first thing I do is map out the air flow, so it’s ‘sudden’ reappearance can feel like true magic.
Santorini in August: the sea temp at 25°C (77°F) matters more than you think
That’s the difference between a swim that cools you and one you brace for. In August you can be in the water at seven in the evening and not shiver coming out.
And the wind is the reason none of this becomes unbearable: the meltemi blows from the north through July and August, often 20–40 km/h in the afternoon, which is what keeps this island cooler than the mainland.
The trade-off is real: the same wind makes the caldera viewpoints gusty and cancels boat trips. If a catamaran day matters to you, build a spare day around it.
The island already solved the heat— digging into the ground
Here’s the thing the beach-club marketing won’t tell you: Santorini has had climate control for hundreds of years.
It’s called yposkafa (υπόσκαφα) and it’s dug into the volcanic rock instead of standing on top of it, which is where the name comes from. The porous lava stone holds nearly the same temperature all year round, so a carved room sits below the 20s°C (low 80s°F) while the street above it burns at 33°C (91°F).
The canaves—the carved cellars where this island people make their wine—are the working version of the same idea. There used to be over three hundred of them. Some, such as Canava Roussos, continue the tradition as closely as possible, while others hold art, and either way, there’s nothing quite like the sheer relief of walking into one in the heat.
An August afternoon built around canavas and shaded courtyards is comfortable in a way no list of “start early, drink water” tips can get.
Santorini in August: the Clock
Here’s the day shape I use, and the one I’d give you if you asked me at a café:
Summer mornings are for slow walking, because the villages are cool and the lanes are empty.
Middays are for being inside or in the water. Lunch long and slow, a canava visit, a swim. Fighting for a viewpoint at 2pm in August is how the island breaks people.
Late afternoon belongs to the wind, terraces, courtyards, and west-facing lanes coming back to life.
Evening is for everyone—which is its own subject, and the next posts are going to cover it: where the crowds go hour by hour, and the real magic of Santorini summer nights.
What about August 15?
The biggest day of the Greek summer—the Feast of the Dormition of the Virgin Mary (Dekapentavgoustos)— lands in the middle of the month. Everything the guides say is true: fullest ferries, fullest roads, busiest week. What they don’t say is what the day is for, and what it looks like in a village that’s been forgotten by mass tourism.
I used to live in Emborio, the biggest village in the Cycladic islands. It felt like half of the island’s population was at the main square, and the grill smoke actually did cover the sky.
Santorini in August: Frequently Asked Questions
Is Santorini too hot to visit in August?
No, but the middle of the day is too hot for active sightseeing without breaks to cool down in the shade. Daytime highs run 30–33°C (86–91°F), with heatwave spikes above that. The meltemi wind keeps the island cooler than mainland Greece. Plan walking for morning, interiors or swimming for midday, and terraces for the windy late afternoon.
Is Santorini cooler than Athens in August?
Usually, yes. The meltemi wind keeps the Cyclades several degrees below the mainland, which regularly passes 40°C (104°F) in a heatwave. The trade-off is gusty afternoons that can affect boat trips.
What time should I do outdoor activities in Santorini in August?
Before 11am or after 5pm. Mornings are the coolest and emptiest hours in the villages; late afternoon brings the wind back. The hours between belong to long lunches, cool interiors, and the sea.
Can you do walking tours in Santorini in August?
Yes—in the morning, with time indoors during the hottest hours. My village walks run early in summer, through lanes that hold shade and villages built to manage sun and wind. Midday walking in August is something I won’t sell you.
What is the weather like in Santorini in August?
Hot, dry, and windy. The average high is around 27°C (81°F) and the average low around 22°C (72°F), with the hottest days reaching 33°C (91°F) or more. Rain falls on roughly one day in the month. Expect 11–12 hours of sunshine a day and a UV index around 9, which is very high.
How warm is the sea in Santorini in August?
About 25°C (77°F), the warmest of the year. Swimming is comfortable at any hour, including early evening. The east-coast beaches at Kamari and Perissa are more sheltered than the wind-facing ones.
Does it rain in Santorini in August?
Almost never. August and July are the driest months on the island, averaging about one rainy day and a millimetre of rain. You can plan an August day without a weather contingency — the thing to plan around is wind, not rain.
Santorini in August: If your dates are fixed, stop reading warnings
Half the August content online ends with “consider September.” That advice is useless to you if the flights are already booked, and you don’t need to be warned—you need a plan.
A private Santorini tour in August is mostly a scheduling problem. If you want the day designed around the heat instead of despite it, then you’re in the right place.
Tell me your dates, and I’ll take it from there.