A status yellow snow and ice warning is in place for 18 counties.
It covers all of Connacht, Donegal, Monaghan, Cavan, and all Leinster counties – except Wexford and Kilkenny – and is in place until 6 this evening.
The Irish Coast Guard is warning people to stay away from the water as wet and windy conditions are expected.
Yesterday evening the Irish Coast Guard activated Waterford City River Rescue following reports of a boat adrift in Mooncoin with a person on board. The area was searched by the crew and the Irish Coast Guard helicopter Rescue 117. The boat and person were successfully located. The person was taken to Waterford University Hospital by the National Ambulance service where their condition is currently unknown.
A swimmer was rescued at Sandycove in Dublin yesterday morning, while a windsurfer was rescued off Garrylucas Strand in west Cork.
Irish Coast Guard spokesman Ger O’Flynn says conditions are treacherous and even seasonal swimmers must be cautious.