We are thinking of stopping in Stockholm in mid-May on our way home from a vacation further south in Europe. Rick's show on Stockholm features ferries, islands, and waterfront restaurants which all look wonderful. Will those things be fully open and operating at that time of year or will they be limited? Rick's tour information (Scandinavian tours only start May 7) says that weather and crowds are favorable during May, but the tour's few water-related activities may be some of the only things operating at that time. Advice?
The ferries are part of the public transportation network, they run all year. Although some routes are a bit more frequent in the summer, and a few routes are summer only. Not sure what restaurants are mentioned, but outdoor seating should in general be available in May.
As for the islands, they are part of the landscape so they are always open and operating. As much as an island can be said to be operating.
I agree about weather and crowds, May often has a lot of sunshine. There might be a few places in remote areas that are closed or only open on weekends in May but it shouldn't refrain you from visit, for example you won't be eating at each end every restaurant anyway. The archipelago is more about scenery than opening hours.