Safety
Oslo is generally a very safe city for travelers. It has one of the lowest crime rates in the world and the residents are helpful and respectful. Only a few specific neighborhoods, where e.g. drugs are traded, are best avoided.
Public transportation is safe to use at all hours.
However, as with any major city, it's always smart to stay vigilant and aware of your surroundings, especially during evenings. Follow basic safety precautions such as watching out for pickpockets, not walking alone late at night in deserted areas or leaving your belongings unattended.
Traffic regulations are strict and draconian.
Health
Health care in Norway is of a very high standard, but quite expensive. Make sure you have a European Health Insurance Card, available from your mutual insurance company, and good travel insurance. Many places are inaccessible to ambulances.
Don't forget your usual medicines. It is very difficult to obtain medication without a prescription from a Norwegian doctor and to get a quick appointment with a general practitioner.
If you have a problem, go to the Emergency Medical Centre (legevakt) located in Trondheimsveien 233, building 40 Aker Hospital and be patient.
Weather
In June, Oslo generally has pleasant temperatures and high rainfall (averaging around 100 mm/month). Daytime temperatures hover around 20°C while nights can cool down to about 9°C.
