Scandinavian travel in early October

It's almost impossible to say without more details about you and your trip. Are you going on a city trip or a nature trip? Will you go hiking an spend time in the mountains? How far north will you be going? Scandinavia + Finland is a vast region with greatly variyng climates.

It goes without saying that Morten is correct. I would just add that we were in Odense and Copenhagen in late September/early October last year, and the weather was very pleasant, high 50s or low 60s every day.

As a first-time visitor to any of the Scandinavian countries, (and will be traveling with a 7-yr old), I plan to do 70% city and 30% nature. I'd like to hit the major city/town sights in each country like Copenhagen, Odense, Stockholm, Olso, and Bergen. And maybe side excursions to nature sights. I read that Norway in a Nutshell is a good way to get a "light" dose of nature. We also like hiking, but not too strenuous (e.g. Half Dome strenuous) that requires a whole day. Something that can be completed in 4-5 hours with views is preferable. Thank you so much for responding.

Thanks for the vote of confidence Steve, I keep trying to explain to my girlfriend that I am always correct, but she seems to disagree.

Regarding the overall weather it can be very pleasant in October as Steve writes, but it could also be rainy and misserable, you never know. Denmark and southern Sweden have a maritime climate, where it is never really cold or really hot, so October won't be very cold, but it could just be boring, grey and rainy. Bergen and western Norway is warmed by the warm ocean current of the Gulf Stream, so it's very mild despite being so far north. It does however rain A LOT especially in Bergen. Sweden and Finland have a continental climate, which means hotter summers and very cold winters and a dryer climate.

If you are mainly visiting cities you should be less affected by bad weather than if you intent to visit nature. Most sights in cities will be open, except the obvious open air activities (like tivoli Gardens in Copenhagen, which close for the winter in September).
For hiking in Norway, check out the norwegian tourist associtation at www.dnt.no. I don't know which hikes will be open in October, since I have only visited Norway in summer or winter.

Cool, thanks. Are transportation schedules scaled back in October or about the same year around? E.g. transportation for tour buses or trains that only serves tourist destinations. I'm assuming normal transit like city bus/metro, trains from city to city, country to country, or ferries remain unchanged?

We were in Copenhagen this past January. Tivoli was closed. Here are the Tivoli dates: http://www.tivoligardens.com/en/praktisk/aabningstider Your 7 year old will be disappointed.

Climate statistics:
https://www.yr.no/place/Denmark/Capital/Copenhagen/statistics.html
http://www.yr.no/place/Norway/Oslo/Oslo/Oslo/statistics.html

Re Appropriate Clothing
http://www.lifeinnorway.net/2013/11/no-bad-weather-only-bad-clothes/

“THERE’S NO SUCH THING AS BAD WEATHER, ONLY BAD CLOTHES” Of all the
Norwegian phrases out there, I’d wager it’s this one you’ll encounter
first. Most likely before you even land in the country, if you’re
(un)fortunate enough to be sat next to a native on your flight.

Foreigners are often drastically underprepared for the Norwegian
winter. Actually even more so for the spring and autumn, when you
frequently experience all types of weather within a couple of hours.
Norwegians take great glee in directing this phrase at all
damp-looking foreigners, with the excitement of thinking they’re the
first to ever share this advice.

We're skiers so what is bad weather to the average tourist may be good weather (i.e. snow) or great weather (temperatures below -2C).

Are transportation schedules scaled back in October or about the same
year around?

Urban life doesn't shut down just be cause its Fall. However, Fall in mountain resort areas is the in-between summer hiking and winter skiing. Transportation to mountain areas may be limited.

Norway's Nutshell tours are year round, so not an issue. (Not active other than walking between trains, boats and buses). In Oslo, you can take the T-1 metro to Holmenkollen or other hill top stops and hike/walk the Nordmarka forests trails: http://www.visitoslo.com/en/articles/nordmarka-forest/

The vast areas of untouched nature that surround Oslo are just 20
minutes from the city centre. The Nordmarka forest represents a source
of recreation that is frequently used by the city's inhabitants, but
also more and more visitors, both in summer and winter. Can any other
capital cities offer skiing, kayaking, ice skating and island hopping
– all within the city limits?

But first visit the Holmenkollen ski museum and jump tower for a panoramic view of Oslo.
http://www.visitoslo.com/en/product/?TLp=496475

Thank you, everyone, for your advice and insights. I'm anxious to see these places in Fall. Note to self to pack extra warm "winter" clothes. I live in northern California, and we have two seasons - wet/warm and dry/warm - with recent draught years, it's just dry/warm or dry/hot.