Two separate weather warnings are in place for a number of counties along the Atlantic coast.
A Status Yellow rainfall warning came into effect for Donegal, Galway, Leitrim, Mayo and Sligo at 9am, and will remain in place until 12pm tomorrow.
Heavy rain showers are expected in the northwest, with accumulations of 30 to 50mm expected.
Met Éireann has warned of possible spot flooding in areas.
The northwest, and particularly Co Donegal, was badly affected by heavy rains at the end of August which caused significant damage to property and infrastructure.
A Status Yellow wind warning is also in place for Donegal, Galway, Leitrim, Mayo, Sligo, Clare, Cork and Kerry.
The weather service said a developing low pressure system in the Atlantic will bring a period of strong and gusty winds to all provinces, but strongest in Atlantic coastal counties.
Wind speeds of up to 65km/h are expected, with gusts of up to 110km/h.
Winds will be strongest in exposed hilly and coastal areas, with high seas expected.
The wind warning came into effect at midday and remains in place until 9am tomorrow.
The Cliffs of Moher visitor centre has requested people to stay away from the centre for the rest of today due to high winds blowing in the area.
The centre has tweeted that gusts of 130kp/h have been recorded in the area.
Visitors arriving at the centre are being advised not to go up on the cliffs but the visitor centre remains open.
