The Children's Hospital for Wales in Cardiff has been closed due to damage caused by heavy rainfall.
18 children being treated there have been moved to other wards at the University Hospital of Wales.
The hospital was closed and patients moved on Monday afternoon.
Nobody was injured.
Cardiff and Vale University Health Board says it doesn't expect the hospital to reopen before the end of the week, as damage to electrics is examined.
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Variable cloud and clear spells overnight with isolated showers mainly in the north.
Becoming drier and brighter from the northwest during the day, but with the risk of scattered, locally heavy, showers developing later.