The royals attended a parade at Cavalry Barracks in Hounslow.
The Met Office had issued five weather warnings covering large swathes of the UK ahead of an unsettled weekend.
A poll ahead of the walkouts suggests a majority of the British public support UK students who first ditched lessons on February 15.
The event focused on youth and comes as the Duke and Duchess of Sussex prepare for the birth of their baby.
The weekend weather deteriorated across the country, bringing snow and strong winds.
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