The Queen will spend the day resting after suffering symptoms of gastroenteritis, Buckingham Palace said.
She was due to attend a military celebration in Wales today during the city's St David's Day celebrations, but has been forced to cancel her planned engagements because of the sickness.
She will instead spend the weekend at Windsor, a palace spokeswoman said.
More top news
Donald Trump has slammed Alec Baldwin's latest impression of him as "unwatchable" and "sad".
The early risers will notice a touch of frost and pockets of fog first thing.
Austria is set vote for its new president again - and possibly elect the first far-right head of state in Europe since World War Two.