2 guides, each rated 1 to 5 with the reason — and two lists per place, where you are comfortable and where to pay attention. Nowhere is called dangerous; the specific thing is what helps.
Very safe, and comfortable to walk alone at night in the central districts. Pickpocketing happens in Gamla Stan and on the T-bana in summer. In winter the ice underfoot and the four-o'clock darkness are what actually catch visitors out.
Comfortable: Östermalm · Södermalm · Vasastan · Kungsholmen · Gamla Stan
Gamla Stan — and the T-bana in summer, for pickpockets working the crowd
Stockholm Central Station — and Sergels torg late at night
Ice underfoot from December to March, and four o’clock darkness, which is what actually catches visitors out
The people are not the risk here; the cold is. At -30°C exposed skin freezes in minutes, and the tour operators lend the suits and boots for that reason — wear them. Do not drive at dusk without watching for reindeer, and tell somebody where you are going on any trail.
Cold, which is the entire safety question: at -30°C exposed skin freezes in minutes and the operators lend suits for a reason
Reindeer on the road at dusk, which is the commonest accident here
Walking onto a frozen lake or river without local judgement of the ice
Mosquitoes in July, which are genuinely extraordinary and which people underestimate
The ratings are this site's own, from the guides' authors and the corrections readers send in; they are not an index. Read the general advice in travel safety tips.