Schools were closed and electricity failed in several parts of Central and Eastern Europe on Monday as a cold snap moved in from Scandinavia, with Poland seeing overnight temperatures plunge to minus 23 degrees Celsius.
The Polish weather service issued safety warnings for most of the country as temperatures are set to plummet further this week.
Around 2,200 households were without power in the northeast, where school bus services were cancelled.
"Due to the cold, there were problems with school transport," regional government spokesman Krzysztof Guzek told the PAP news agency.
In Latvia, a temperature of minus 29.5 Celsius (minus 21.1 Fahrenheit) was recorded in Daugavpils, the country's second-largest city, with weather forecasters predicting similar arctic conditions through the week.
Hungary's national weather service warned of wind gusts of up to 90 km/h (56 mph) in the northeast and temperatures slipping to minus 12C in some areas by Friday and Saturday.
Strong winds of nearly 100 km/h blew off roofs, brought down trees onto roads and downed electricity poles and power lines in some parts of the country.
Hungarian authorities warned in particular to ensure that pets and animals in shelters or strays are not exposed to the extreme cold.
"Sub-zero temperatures can pose a threat to our pets, and it is particularly important that we all take action to protect animals during this period," Peter Ovadi, the official responsible for animal protection, said in a statement.
In Moldova, around 22,000 clients were without electricity on Monday as the frigid temps forced flight cancellations and delays at Chisinau Airport.
Public transportation in the capital was also halted and schools were closed until Thursday.
Snowfall forced two flights to be diverted from Iasi Airport in Romania and sections of main roads closed in eastern regions.
Germany's weather service said that temperatures could fall as low as minus 15C overnight, but added that it was not unusual for the country to see such temperatures in January.
"What was abnormal, however, was how 'hot' it was at the beginning of January in Germany," a spokesman for the German meteorological agency, Andreas Walter, told AFP.
Temperatures had risen across much of the country at the start of the year, hitting 17C in Frankfurt.
"Between 2018 and 2023, the months of January were actually much too hot when compared to the 1961-90 reference period," Walter said.