Temperatures in south-west Finland could reach 10 degrees Celsius on Wednesday, according to the Finnish Meteorological Institute (FMI).
The weather watching agency said the day will likely be warmest on the semi-autonomous Åland islands in the Finnish Archipelago. The highest-measured temperature on Åland was 10.9 degrees on 6 January, 1973, according to FMI meteorologist Cecilia Wulff.
"We'll see if a new record is set, but it'll be unusually warm in any case," Wulff said.
The weather has also been unseasonably warm across Scandinavia this winter. Last week the temperature in Norway reached 19 degrees and that warm southerly wind - often referred to as a föhn wind - is now blowing across the Nordic region.
Föhn winds are dry, warm wind systems created on the downward side of mountain ranges. The resulting winds can raise relative temperatures by as much as 14 degrees very rapidly.
Wulff said the weather will be unusually mild the rest of the week as well, saying that temperatures in Finland will likely continue to be above normal for the next four weeks.
However, the weather will likely also be variable this week and temperatures will likely dip below the freezing point on Friday and Saturday, but Finland will thaw out again on Sunday, Wulff added.
The average temperature in southern Finland this time of year is -5 degrees Celsius, with an average high of -1 degree and average low of -9 degrees. The typical temperature in Lapland's Rovaniemi this time of year is about -16 degrees, according to the FMI.