My husband and I would like to spend a week in Copenhagen and Stockholm but our schedules make it difficult to do it any month before October. I see from Rick’s book that most museums and sites have abbreviated hours, so is a trip in October still worth it? Thank you.
I know Rick Steves say you should visit Scandinavia in the summer months. While this is a good idea for smaller towns and islands, it doesn't apply that much to the Scandinavian cities.
If you want long daylight hours, sun and warm weather, you should visit during the summer. But in this part the world, there are no guarantees - if you want good weather guarantee, Scandinavia is the wrong destination.
However, if you can subscribe to the "there's no such thing as bad weather, just improper clothing" mentality, visiting in October shouldn't be a problem for you.
Most things will be open in Copenhagen and Stockholm in October, maybe not for as many hours as in July, but still with reasonable hours. A few things may be closed off-season, so if you have any must-see's it's a good idea to check their opening hours and seasons before you book your trip (this applies to Tivoli Gardens, for example).
Note that there are school breaks in week 42 in Denmark and week 44 in Sweden. This generally means museums and attractions will extend their opening hours.
Too generic question and the detailed one you can answer yourself by looking into the opening hours of sights and museums you want to visit.
Or try to answer the opposite question: Why it should not be worth it to share worldclass destinations with less tourists?
My wife and I did nine nights in Denmark in late September and early October 2015. We had no issues with anything being closed or having hours that were too short. We never had to wait for anything, and often had places nearly to ourselves, which was wonderful. If I recall correctly, the weather was still pleasant - maybe 55 to 65 most days (but maybe we got a bit lucky). I do note that Tivoli is closed (except towards the end of October). Didn't bother us. I would 100% recommend the trip.
Short answer: Yes, Scandinavia is worth a trip in the autumn. (It's a great winter destination as well.)