A temperature of -42°C was measured in Hedmark county on Wednesday - the coldest official temperature recorded in the country all winter.
In Hedmark's Tynset municipality, the second coldest official temperature in the country was recorded on at 37.3 degrees below zero.
"The most northern area in the south has the least cloud and lowest temperature," Per Egil Haga of the Norwegian Meteorological Institute told NRK.
Further south, clouds are taking the most extreme edge away from the cold, but strong winds are causing the air to feel similarly icy.
At the Blåsjø lake in Agder and Rogaland, windchill has resulted in temperatures feeling as cold as -40°C, NRK reports.
"It's almost dangerous to go out in the western mountain areas," meteorologist Terje Alsvik Walløe told NRK.
Even short periods spent outside in such cold can lead to frost-related injuries and hypothermia, the broadcaster writes.
"Many years can go by without us seeing such cold weather in the south. This is not everyday stuff," Walløe added.
The extreme conditions are the result of a front from Siberia which is currently the cause of cold weather in southern Norway and large parts of Europe. Media in the United Kingdom have dubbed the weather the "Beast from the East".
"It will not develop too much. It is a high-pressure system that gives clear winter weather. We will have the same type of weather tomorrow," Haga said to NRK.
READ ALSO: Temperature in Norway drops to -32.5°C