Met Eireann has issued an advisory warning that Ireland will face "very wet and windy weather" for several days.
The national forecaster said that as the weekend ends, the whole country will suffer from a "period of unsettled weather", with heavy rain and flooding both set to hit.
A spokesman said: "Conditions turning unsettled by the end of the weekend, with a spell of very wet and at times windy weather on Monday and Tuesday.
"Persistent and locally heavy rainfall, coupled with high soil saturation levels, brings a risk of river and surface flooding.
"Unusually high tides combined with strong winds gives an elevated risk of coastal flooding. Warnings will be issued on Sunday."
Today will see a mix of sunny spells and scattered showers, before heavy rain arrives later tonight.
The forecaster explained: "Rain will affect the north and northeast early tonight, but will clear away to the northeast overnight.
"Elsewhere, there will be some patchy light rain or drizzle at first, but more persistent and heavy rain will move into the southwest later in the night.
"Generally cloudy conditions will keep minimum temperatures around 8C to 12C. Light to moderate southerly winds will gradually freshen overnight, becoming strong near coasts later.
"Tomorrow will be a cloudy, wet and breezy day. Persistent rain across the southwest early in the morning will spread to nearly all parts of the country by late morning and will be heavy at times, especially in the west and north.
"There will be a risk of river and surface flooding as soils remain or become saturated.
"The rain will ease across the southern half of the country for a time later in the afternoon, but further heavy rain will move in from the southwest during the evening and become widespread.
"Fresh southerly winds will persist through the day, with stronger winds near coasts. Highest temperatures of 12C to 14C."
They added: "Low pressure is currently forecast to move northeastwards over Ireland during Tuesday, causing strong southerly winds in the south and east.
"Heavy and persistent rain in northern areas on Tuesday morning is expected to clear away to the north during the morning, but through the rest of the day further outbreaks of heavy rain are forecast to move northeastwards across the country as the low pressure system tracks over Ireland. Highest temperatures of 13C to 15C."
