Temperature's rising; it's now at 0 C (32 F). Whew.
I saw a father with his toddler on the ice, but I wasn't sure it's safe. I wanted to warn them, but just wasn't sure if they were really in danger, so I walked past as fast as I could so I didn't have to think about it. You can make out a line in the snow-covered ice in this photo and that's where there's current underneath or something. The ice is thinner there. The father and his kid weren't far from a couple of seams like this, but they were only a few feet from shore.
Swan update: It's a mute swan ("knoppsvane"). It managed to hold its head in such a way that I finally could see the bulge on its bill which gives it its Norwegian name. Very likely a juvenile because of the grayish coloring of head and neck.