In the Republic of Ireland more than 200 members of the military have been deployed to help deal with flooding.
Homes and businesses in Cork city were flooded when the River Lee burst its banks and the collapse of a quay wall beside Mercy Hospital forced the closure of the Accident and Emergency unit.
The Electricity Supply Board said its dam at Inniscarra was dealing with eight times the amount of water it normally handles, and that they had been forced to release water downstream towards the city.
In Galway, a coastguard helicopter rescued a family whose house was surrounded by rising floodwaters.
All five members of the family, including an 87-year-old woman, were winched from the house in Kilbeacanty by the crew in an operation that lasted almost three hours.
The west and south of the country have been worst affected, with up to one metre of water in some areas.
A number of roads are closed and some bus and rail services cancelled. People have been advised not to travel unless necessary.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.