Skaters should keep off lakes and canals because the ice is still not strong enough for outdoor skating, despite two nights of heavy frost, the Dutch skating association KNSB said on Monday.

Websites set up by skating enthusiasts refer to dozens of places where the ice is ‘reasonable to good’ but the KNSB says much of the ice is still unreliable.
For official outdoor skating tours, the ice must be at least 12 cm thick. The snow and ice left over from the pre-Christmas freeze have also lead to many weak spots in the ice cover, the KNSB said.
Pleasure boats
In Amsterdam, the city council has banned pleasure boats from using many city centre canals in the hope that they too will freeze over for skating.
The big freeze is set to continue for the next five days at least, and there is an 80% chance of it continuing for the next 10, according to the KNMI weather bureau.
But the continuing snow makes it unlikely the ice will thicken enough for an Elfstedentocht – the spectacular 200 km race between the 11 cities of Friesland. The event was last held in 1997.
‘In fact, it first needs to thaw so that the old, bad quality ice disappears. And then if it freezes again and does not snow, you’ll get ice that is strong enough,’ Ron Wiersma of weather bureau Meteoconsult told the Volkskrant.