Driving conditions across Finland are expected to be hazardous on Sunday, particularly in central regions, due to heavy snowfall and possible freezing rain.
Weather forecasting service Foreca issued the warning on Saturday.
The company advised delaying Christmas travel until Monday, if feasible.
In southern Finland, precipitation will mostly fall as rain, which may improve conditions on the main roads.
However, side roads are likely to remain extremely icy and slippery. Foreca also cautioned pedestrians to take extra care as pavements could be treacherously slick.
Foreca warned that those travelling north from southern Finland on Sunday could face several hours of driving in snow.
Snowfall is expected to gradually move northward throughout the afternoon and evening, reaching areas as far as North Ostrobothnia and southern Lapland by nightfall. Snow accumulation is forecast to be between 5 and 10 centimetres in most affected areas.
The Finnish Meteorological Institute (FMI) has issued widespread warnings for poor driving and walking conditions across southern and central Finland.
With more travellers on the roads over the festive season, there is also a heightened risk of accidents — here are some tips to stay safe.
Calm start to Christmas traffic
Despite the weather warnings, Christmas traffic has so far been relatively calm. Many travellers appear to have heeded advice to delay their journeys until Monday.
According to Jori Hildén, a traffic operator at Fintraffic's Road Traffic Centre, traffic over the weekend has been unusually quiet.
"There haven't been any significant jams. Of course, today's driving conditions are more challenging, and drivers have been urged to wait until Monday to set off for Christmas celebrations," Hildén told Finnish News Agency STT on Sunday morning.
He noted that road traffic on Saturday was even quieter than a typical Saturday.
"It's possible we won't see much congestion at all, as Christmas traffic is spread across four days," Hildén speculated.
There was, however, a major collision on Highway 4 in Mäntsälä on Saturday night.
The chain collision involved 13 vehicles and 28 people, but only minor injuries were sustained as a result.
The accident was caused by smoke from nearby burning Swedish torch logs said Detective Chief Inspector Henri Karjalainen of the Eastern Uusimaa police.
The smoke from the fires obstructed visibility on the road. The fires were part of a youth Christmas event organised by the Central Union of Agricultural Producers and Forest Owners (MTK).
MTK's communications director Jussi Martikainen said that the Swedish torches have been used traditionally for decades all over the country.
"This is the first time that there's been a suspicion that something has gone wrong with the tradition. It's a great shame that such an accident has occurred. And the most important thing is that there were no serious injuries," Martikainen said.
Slippery roads
Road maintenance is particularly busy and busy today, said traffic operator Juho Anttonen from Fintraffic's Road Traffic Centre.
"Phone lines have been busy all day long."
Motorists should be careful in Christmas traffic. Road surfaces are particularly slippery in Southwest Finland, Häme and Central Finland, Anttonen said, based on reports received by Fintraffic.
"Most of the main roads have already been sanded or are slippery, but on smaller roads conditions can still be quite slippery. There's simply not enough equipment." Anttonen added.
Anttonen said that motorists complaints about road conditions will still get through to road maintenance, but they will likely take more time to fix those roads.
Article updated at 16:54 to add Anttonen comments.
Article updated at 17:22 to add MTK and Martikainen comments.