A storm set to hit central parts of the country on Wednesday could bring up to 20 cms of snow north of Lappeenranta and Hämeenlinna and to the south of Kuopio.
A low-pressure zone will move east across southern Finland from the southwest, the weather forecast said.
"Low pressure will first bring rain, but it will get snowier at night. There will be dense snowfall during the afternoon and heavy snow could accumulate on trees," Yle meteorologist Anne Borgström predicted.
Coastal areas in the southwest as well as southern Finland will see rainfall until Wednesday evening when precipitation will turn into sleet. There is also a possibility of snow on Thursday night.
"The amount of snow in the south could be very low — there are chances of a very light snowfall."
The forecast predicts snow in Northern Karelia up until Thursday night but the rain will recede by morning.
Northern Ostrobothnia and Lapland will be spared from the storm and will remain cloudy with light rain showers on Wednesday.
South and southwestern sea areas are likely to experience stormy winds on Wednesday afternoon and evening, with gusts reaching up to 24 metres per second.
'Black Christmas' in southern Finland
As the storm drifts eastward, Thursday will see a change in weather conditions across the country.
"Cool, even sunny and a bit colder — Thursday will be what we want this time of year," Borgström said.
However, things will take a gloomier turn before Christmas in southern Finland.
"As early as Friday, some rain from the west will arrive again and the whole weekend will be gloomy. The beginning of the week doesn't look much better either," Borgström added.