Santorini, Naxos, Crete

May is early season so you might get some cooler days but it warms up fast. The wild flowers are out and the hotels and tavernas are all ready for the new season.
By October the Greeks have been working 12 hour days for 5 months and are ready for the off season. A few years ago we stayed in Naxos for the first week on October. The tavernas and hotels were closing for the season. We were the last guests at a lovely hotel. and as we left they shut the doors and locked them behind us.
May will be the best choice. In fact we are heading back to Greece in May next year.

I would go for May as well. I would go later in May as there is more rain earlier in the month.

I am heading back to Greece in May next year again also!

Greetings all. Just returning from 2 weeks in Greece and 5 days in Naxos (first time to Naxos). The weather was lovely and the water was refreshing. The island was beautiful and lively with tourists. While the hotel had many guests the manager let me know they were closing in a few weeks. If you do go in October, I’d aim for the first few weeks and not later. I can’t speak for Santorini or Crete.

If you want to beach/swim, definitely October. We were in Santorini in June, and while I wouldn't say "cold", let's say the water was "brisk". I'm told it warms up over the summer and stays warm into autumn.

Much depends on what you're used to ... many US southerners can't abide even a bit of a tingle ... midwesterners who lake-swim, and NY/ CT people who do Long Island Sound have no problem with a first-minute ooh!. Being a May visitor for many years, I 'm fine after May 15, have swum 25+ islands plus All over Peloponnese. After 60 secs of Brisk, you get moving and it's lovely, and llively ... i've stayed in til my fingers wrinkle. Always good to start with beaches that slope for a few yards... Santorini, on the Caldera side you are jumping into an ocean Cauildron a ?mile? deep! It never gets mellow.

Late (very end of) May or early (first half) October.

In one of your previous posts, I read that you wanted to "experience the culture, food, and people of Greece."

So, regarding swimming, are you going to travel 7,000 miles to spend most of your time on a beach?
I don't think so.
Especially since, whether it's May or October, it's possible to swim. The notion of cold is very subjective and depends on each individual.

Hi Meredith - I popped on here a month ago to ask the identical question. The resounding response was May. However, I did more research and based on what we would be pursuing (archaeological sites, wineries, travel around the island), we decided on October. We will be in Turkey/Greece for two weeks prior and this will be our final week of respite after a rigorous tour. I very much wanted to see Santorini w/ the least amount of people and we will have only one day w/ three cruise ships and the rest one at most and a few days with zero ships.
We booked the honeymoon suite with private balcony and caldera view at Blue Dolphins on Santorini for a steal. Then, after all the booking Matt Barrett of greecetravel.com wrote a blog on why October is the prime month for Santorini and many greek islands. I attempted to locate it for you to no avail.
We're headed to Hungary/Croatia/Slovenia in May for independent travel instead :-). Happy travels!

We've just spent the last two weeks in Santorini, Naxos and Rhodes and apart from a miserable day and a half of clouds and rain in Santor, the weather was warm and perfect.

Everything appeared to be open and we had a great time.

Still far too crowded for my liking, I'd hate to be there in high season.