Met Éireann said temperatures are set to dip to between -1 and 4 degrees tonight, with fog and patches of frost expected to form, especially under prolonged clear spells.
The weather service said any fog, mist or frost will clear early tomorrow morning and most areas will be dry during daylight hours.
It will start as a sunny day, but cloudy outbreaks of rain and drizzle will develop in the west and northwest during the afternoon.
Met Éireann said it will be milder and breezier than recent days, with highest temperatures of 8 to 11 degrees.
Tomorrow night will see outbreaks of rain moving southwards over the country, with drier and clearer conditions following from the north.
It will remain quite mild with lowest temperatures of 6 to 9 degrees in moderate south westerly winds.
Any lingering patchy, light rain will clear to the east on Thursday morning with drier, bright conditions and sunny spells extending countrywide by afternoon. Highest temperatures of 9 to 11 degrees are expected in mostly moderate westerly winds.
Temperatures are set to drop again to between -1 to +3 degrees on Thursday night with frost and fog developing.
Met Éireann said cloud will increase on Friday morning with outbreaks of light rain or drizzle - most frequent in the west – and highest temperatures of 10 to 12 degrees.
Friday night will see outbreaks of rain continuing with the heaviest and most frequent falls in the west of the country.
It will become milder overnight with lowest temperatures of 8 to 10 degrees in moderate to occasionally fresh southwest winds.
Saturday will be cloudy with outbreaks of rain - heaviest and most frequent in the north and west. After a very mild start to the day, with highest temperatures of 8 to 14 degrees, it will become cooler as the day progresses in moderate to fresh southwest winds.
Met Éireann said there is “a bit of uncertainty” about Sunday’s weather, but there is the potential for “a period of wet and blustery conditions”.
After a mostly cloudy start, it said a band of wet and windy weather will sweep across the country during the afternoon, with the heaviest rainfall over the north of the country. Afternoon temperatures on Sunday will range between 9 to 12 degrees in fresh and gusty westerly winds.