Helsinki then Jyväskylä in mid-July must sees?

I don't know Jyvaskyla (please forgive missing diacritical marks) at all but enjoyed two nights in Tampere--three nights would have been better for me, but I like exploring attractive cities even in the absence of big-name sights. Google Maps is telling me Tampere is just over 1-1/2 hours from Jyvaskyla by train. I haven't checked the Finnish rail website to be sure, but it appears trains between Helsinki and Jyvskyla travel through Tampere.

Helsinki itself has a lot of Art Nouveau architecture, a particular favorite of mine, and quite a lot of art museums for a city its size.

I've never been to Jyväskylä and don't know much about it to be honest. So I'm just going to link to https://en.wikivoyage.org/wiki/Jyväskylä and https://visitjyvaskyla.fi/sv/

Regarding the trains, you find all information at www.vr.fi

(Also note that there are no diacritical marks in Jyväskylä.)

Umlauts then? I thought perhaps that term was only used in reference to German worda.

Without diving too deep into linguistics: A diacritic is a small addition to a letter used to change it a bit, such as in the case of umlauts, when a sound is changed. There are many different examples, including the two dots, ¨, common in German where they are used to modify A, O and U to Ä, Ö and Ü.

In Finnish however, there are no umlauts and A and Ä are considered two different letters. Just like P and R, I and J, and O and Q are different letters.

Thank you for your replies! I will keep researching; it sounds as though we may want to rent a car once we get to Jväskylä. As to the double dotted Ä…my iPhone just adds them for me. :)

This blog might be of help. Looks like lots to do from a local perspective.
https://herfinland.com/jyvaskyla-things-to-do/

https://www.coe.int/en/web/cultural-routes/alvar-aalto-route

It might be worth looking into this cultural route.

I think his footprints are around Jyväskylä

That is a very good train ride into the interior going from Helsinki to Jyväskylä.

Terve! (Hello in Finnish)
I'm glad you are going to Finland and especially to Jyväskylä (kylä means village, not sure about jyväs, but jyvä is grain).
It's a medium sized city in Central Finland. Very walkable. The train-bus station is combined to the same location. Just about 5 minutes away from the city center. It's a young city with a lot of students.
I recommend the Harju Ridge and Vesitorni, water tower/observation tower and the Nero Steps (over 100 steps to climb up).
https://www.visitfinland.com/en/product/53d8d4f7-2c9f-409c-aebd-3638b285a8b8/harju-ridge-vesilinna-observation-tower/
In the summer there is the Harju evening song played at 8 pm by trumpet, or maybe a recording nowadays. This summer treat goes on until the end of August.
If you are into architecture and especially the famous architect Alvar Aalto then Jyväskylä is the place to visit. There are 29 buildings designed by Aalto in and around Jyväskylä region .
If you have time, you could take a short Lake Päijänne cruise, the lunch buffet or the summer evening cruise. Lake Päijänne is a large beautiful lake, the pearl of Jyväskylä.
I hope you will enjoy your stay in Jyväskylä (I went to high school over there and now my daughter studies at the university over there).
Näkemiin! (till we see you or bye for now)

Thank you, all, for your excellent suggestions! We can’t wait!