Dec in Athens

If you like to stay for a while in a sleepy rural village atmosphere of 2000 inhabitants, which these islands will be in December, with temperatures not exceeding 60F / 65F and some probable showers, yes you can go to an island like the one you mentioned.

We are often in Athens in December. The weather can be changeable but you’d be unlucky not to have some days when it’s warm and sunny enough to sit out at lunchtime in shirtsleeves.

There are organised tours all the year round which take in three of the nearby islands in a day. It’s obviously a matter of taste but I wouldn’t opt for this: a lot of time on a ferry and very little time on each island.

On the other hand a day trip to Aegena is fairly straightforward. It’s an easy trip,from Piraeus on a Flying Dolphin and will give you a taste of the islands. You can book on the day so check the weather before you go.

Janet, who often posts here, has good instructions on doing this so hopefully she’ll see your post and can chip in.

There are locals on these islands so nothing shuts down completely.

They'll always be shops, markets, tavernas and other services open.

May not be the best weather but you may luck out with some mild temps and you'll find far less tourists there and possibly a more "Greek" experience than a tourist experience.