But when it rains?
Of course, there's no such thing as bad weather... only bad clothing! If you decide to stay inside you could have a great time with a good book or a deck of cards... or both - but that's not particularly specific for Öland... ;)
Or, you could use the help of a (certain) good book, a well sorted deck of cards and (if you choose to do it by hand) quite some time to find the location of a small magnetic box at one of Borgholm's interesting but lesser known sightseeing spots.
Interested?
The box is hidden here: