No I mean 5-7. The skiing is rubbish until January but the ground is frozen by the end of October and defrosts in late March/early April. Lots of places have colder winters than here but they do drag on.

I can't really recall when there was snow in Oslo for half a year. Some years were nearly snowless. Officially, the winter period in Oslo is 119 days.

And well north of the city/further from the sea you can feel proper winter better, sure. Even so close as Lillestrøm it's crisper. But again, nothing unusual by North/central European standards.

2 winters ago... Last winter was very mild though.