Eastern Finland is experiencing the bitterest cold. In the provinces of North Karelia, Koillismaa and Kainuu, temperatures hover around -30 to -35 degrees Celsius.
The frostiest location in Southern Finland was Heinola, with a low of -23.1 degrees, while Helsinki was relatively balmy at just -15.
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After a mild start to the winter, frigid air is now pouring into Finland from the east. This Russian blast will keep the country in the deep freeze all week, says FMI meteorologist Antti Jylhä-Ollilla.
Early this week, southern and western areas will experience lows of -15 to -25, while the east and Lapland will get readings between -30 and -35.
There is no sign of a warming trend before next weekend, nor is there any new snow in sight. Mercifully, winds will remain light.
In southernmost Finland, the sun has already gained enough strength to raise temperatures by around five degrees during the daytime. Up north, it still has a negligible impact.