Stockholm in March?

Prices are set by supply and demand. And the winter weather really doesn't break until May as most March months are pretty cloudy.
Copenhagen temperatures don't appear to be much warmer than Stockholm. (We've been to each.) We've also found the weather the end of March to be substantially different than the first week of March.

We often go in Spring and have found end of March ticket prices to be reasonable. But there again, in March/April we're going far south of Scandinavia.

"Museums, exploring, visiting landmarks, trying new foods" sounds as if Munich and Bavaria would be a good place to start.

I haven't been that far north in March, nor would I be willing to visit at that time of year. I love Stockholm, but I wonder whether it could also be windy, which would make it feel colder. Cities on rivers and coasts have often seemed windy to me, and Stockholm is built on a bunch of islands.

If you've only looked at monthly averages so far, you might also check the actual, historical, day-by-day weather statistics available on timeanddate.com. I look at the most recent five years when making decisions about new destinations.

Stockholm weather - March 2023

Use the pull-down box at the right, just above the graph, to display a different month and year. Use the Search box for data on Copenhagen or other cities you're considering.

I have been to Stockholm the first week of March. Luckily it was sunny and in the 40f. I have also been there in mid October. It rained quite abit. I enjoyed both times. Stockholm has the vasa museum, a must see. Swedish food is really good. Stockholm is beautiful. As far as the weather, there's no bad weather, just bad clothing. Have a great time.

If you're used to the weather in California, Stockholm will probably always be really cold.

It is of course impossible to predict the weather that far in advance but March is rarely a cold month, it is usually when winter starts to turn to spring, and it can be very sunny and nice. But it can vary a lot.

including museums, exploring, visiting landmarks, trying new foods

You can certainly do that in March. As well as other things. And there will not be long lines at popular attractions.

And no, Stockholm is not a particularly windy city.

I live in the Bay Area, CA & Uppsala, Sweden which is usually slightly colder than Stockholm. When I arrived April 6, 2023 at Arlanda airport, there had been a large snow fall & everything was white. I recall it stayed on the ground more than a few days, so it must have hovered near freezing, in other years it rained, sometimes it warms up & is lovely. If you're really adventurous & willing to bring warm clothing (maybe you go up into the High Sierras, so you own good winter clothing, a rain coat & puffer coat layer, warm boots, gloves, thick winter pants, wool socks?) I think you could have a great time visiting in March, but it wouldn't be my first choice. And yes, there are lots of things to do indoors, but you'd probably take public transport & the tram out to the Vasa museum, for example, waiting at tram stops is still cold! Taxis are VERY expensive in Stockholm. I think it's the humidity, but sometimes on the water in Stockholm it just feels chillier. Where else are you considering?? IMO, I would look again at airfares & head somewhere further south! But you know what, re-reading your schedule & preferences, IF YOU BRING THE RIGHT CLOTHING, you could have a good time.