How cold is Oslo?

Not horribly cold compared to most of the country. The summers are perfectly pleasant (its 23C and sunny outside at the moment), but a bit unpredictable. In a good year it can be warm from mid May to late September , and in a cold year you can have snow in May and October. When it's cold it's not that cold. read more

However, cold arctic continental and -maritime air masses from the Greenland and Russia, brings the cold winter Norway is known for. The polar jet stream greatly contributes to the flow of the air masses in Norway. read more