Europe crippled by heavy snow
The Eurostar high-speed train service between London and Paris has also been suspended.
In south-eastern England, hundreds of people were stranded in their cars by the snow as emergency services struggled with road chaos.
There were huge traffic jams in Belgium and northern France too.
Having received about five inches of snow, Frankfurt airport was set to remain closed until at least 12:30 p.m., said Stefan Schulte, a spokesman for airport operator Fraport AG.
More than 100 flights had already been cancelled, he added, but the final number was likely to be much higher.
In Paris, some 300 flights from Charles de Gaulle airport – a quarter of the day’s total – were cancelled, along with a similar proportion from Paris Orly.
Brussels airport was also offering a reduced service on a single runway.
The freezing weather in Belgium and northern France also hit rail services, including the cross-Channel Eurostar, which cancelled trains for the rest of the day.
Parts of southern England were coping with a second day of snow and freezing conditions.
Just in the county of Sussex, police dealt with more than 300 traffic collisions in 24 hours.
Among those stranded by snowbound roads was a group of 120 German students who had to stay overnight in the town hall at Hastings on the south coast of England when families set to pick them up could not reach them, the AP news agency reported.
However, officials said they were steadily clearing roads and conditions improved during the day. (BBC)