Temperatures are expected to drop as low as 1C tonight as Met Eireann predicts a wet and unsettled week.
Despite a decent start on Tuesday, weather chiefs believe things will take a turn for the worst on Wednesday.
A forecaster said: "A few showers will affect eastern and southern coastal counties during the day.
"Feeling cold in fresh easterly winds, which will be strong along windward coasts. Maximum temperatures of 8 to 11 degrees.
"Breezy tonight with outbreaks of rain and drizzle spreading to southern coastal districts.
"Elsewhere, it will be mainly dry with some clear spells and just isolated showers.
"Minimum temperatures of between 1C and 4C in midland and northern counties but ranging 5C to 8C elsewhere. Moderate easterly breezes over land but fresh to strong at the coast."
They continued: "Rain will spread across Munster and parts of south Leinster on Wednesday, turning heavy in southern coastal areas.
"It looks set to remain predominantly dry elsewhere drying daylight hours with just the odd passing shower.
"Rain will extend nationwide during the evening. Fresh to strong east or southeast winds and the best of any sunny spells will be in Ulster. Maximum temperatures ranging 9C to 13C."
Thursday looks set to be even worse as the wet and windy conditions become more prevalent nationwide.
They added: "It looks set to be mostly cloudy on Thursday with widespread showers, some heavy.
"Persistent rain will develop in the south during the evening. Highest temperatures of 12C to 15C in moderate southerly breezes."
