Short answer
Late May to June and September to early October. The sea is warm enough to swim (19–24°C), it hardly ever rains, and the island is calmer than in July and August, when the crowds and the meltemi wind both peak. For the warmest sea, go in late August or September; for walking and quiet, April or late October.
- Warmest sea
- Aug–Sep, about 24°C
- Driest months
- June to September
- Windiest
- July and August
- Boat season
- March to November
Santorini is open all year, but it is a different island in April, August and January. What changes is the sea temperature, the wind, the length of the day and how many people are on the caldera paths with you. Our Santorini cruises sail from Vlychada Marina every day from March to November, and this is how the months look from the deck.
Santorini month by month
Daytime highs and rainfall are monthly averages from the National Observatory of Athens station on the island (2013–2025), as listed on Wikipedia. Sea temperatures are long-term monthly averages for the Santorini coast (source: weather2travel). Sunset times are for the 15th of each month, local time.
| Month | Day high | Sea | Rain | Sunset | What it is like |
|---|---|---|---|---|---|
| January | 14°C | 16°C | 53 mm | 17:25 | Quiet and windy; many places closed |
| February | 15°C | 16°C | 41 mm | 17:58 | Cool and grey; the island still asleep |
| March | 16°C | 16°C | 45 mm | 18:24 | Island waking up; first boats out |
| April | 20°C | 16°C | 12 mm | 19:51 | Good for walking; sea still cold |
| May | 23°C | 19°C | 8 mm | 20:17 | Warm days, fresh swims, green hills |
| June | 28°C | 22°C | 4 mm | 20:37 | Long days, warm sea, latest sunsets |
| July | 30°C | 23°C | 0 mm | 20:36 | Hottest and busiest; meltemi wind |
| August | 30°C | 24°C | 3 mm | 20:09 | Busy, windy, warmest sea |
| September | 27°C | 24°C | 3 mm | 19:25 | Warm sea, softer heat, fewer people |
| October | 23°C | 22°C | 15 mm | 18:42 | Still swimmable; calmer island |
| November | 19°C | 19°C | 34 mm | 17:09 | End of the season; first rain |
| December | 16°C | 17°C | 55 mm | 17:03 | Wettest month; local life only |
The best months, by what you want
- Swimming and snorkelling: late August and September, when the sea is at its warmest.
- Long days and late sunsets: June. The sun sets after 20:30, so a sunset cruise ends in the evening light.
- Walking the caldera path from Fira to Oia: April, May and October, before or after the heat.
- Honeymoons: September and early October, with warm water and a calmer island. A private catamaran keeps the boat to the two of you.
- Families with children: June and September, outside the busiest school-holiday weeks.
- Fewer people: April and late October, when most hotels and tours are open but the crowds have not arrived or have gone.
Spring: April and May
Spring is the season for walking. The hills are green, the caldera path between Fira and Oia is comfortable in the middle of the day, and the villages are calm. In April the sea is still about 16°C, so swims are short; by late May it is close to 19°C and most guests get in.
Greek Orthodox Easter falls in April or early May, and the island fills with Greek visitors for that weekend. Bring a warm layer for the evenings and for any time on the water: the air on deck is cooler than on land.
Summer: June to August
Summer is the classic Santorini: long, dry days, a warm sea and every restaurant and boat running. June is the easiest summer month, with the longest days and the sunset after 20:30.
July and August are the hottest and busiest weeks. Fira and Oia are at their most crowded in the middle of the day, and the sunset spots in Oia fill an hour or more before the sun goes down. These are also the months of the meltemi, a dry northerly wind that usually builds in the afternoon. It keeps the heat bearable on land; on the water it makes the afternoon sea livelier. If you are sensitive to motion, choose a morning cruise in July and August.
Autumn: September and October
September is one of the best months on the water. The sea has had all summer to warm up (about 24°C), the meltemi eases, and the island is noticeably calmer after the school holidays. It is the month we would pick for a honeymoon or for anyone who wants long swims at the volcano hot springs and Red Beach.
October is still warm, around 23°C during the day, and the sea stays as warm as in June. The sun sets earlier, at about 18:40 in mid-October, so the sunset comes earlier in the cruise. Towards the end of the month the first rain arrives and some places start closing.
Winter: November to March
Winter is quiet and local. Many hotels, restaurants and shops in Oia and Fira close from November until spring, the sea drops to 16–17°C and December and January bring the most rain and the strongest winds. On calm days the light is clear and the caldera paths are empty, which suits walkers and photographers.
Our boat tours run until November and start again in March. Outside those months most boat tours on the island stop.
Is Santorini worth visiting in July and August?
Yes, if you plan around the heat and the crowds. Mid-summer has the most reliable weather of the year: no rain, a sea warm enough to stay in as long as you like, and every restaurant, beach and boat running. What you give up is space. Oia is packed at sunset, hotel prices are at their highest, and the meltemi can make an afternoon on the water livelier than in June or September.
How to make the most of it:
- Walk the villages early or late. Fira and Oia are pleasant before 10:00 and after dark; spend the middle of the day by the sea.
- Watch the sunset somewhere other than Oia castle. Imerovigli, the Akrotiri lighthouse or the deck of a boat are all quieter.
- Pick the morning cruise if you get seasick. The wind usually builds in the afternoon, so the 10:00 cruise is the calmer of the two.
- Book what matters first. A caldera-view room and a sunset cruise are the two things that sell out.
If your dates are flexible, June and September give you almost the same weather with far fewer people. That is what we tell friends who ask.
When to book
For June to September, book flights and hotels with a caldera view early; they are the first to go. For a cruise in July or August, book once your dates are set. On our cruises you can cancel for free up to 24 hours before, and if we cancel because of the weather you can move to another date or get a full refund.
For what to pack in each month, see what to wear on a catamaran in Santorini, and for today’s exact time, Santorini sunset time.
