However, it will remain mild for the next week.
This morning, December 30, will see rain push into the south and spread northwards to most areas through the afternoon and evening.
"The rain will be heavy at times with a risk of localised flooding,” a Met Éireann forecaster said.
"However, some parts of Ulster will stay dry. Highest temperatures of 11 to 13 degrees in light to moderate southerly winds, increasing fresh to strong in southern areas by evening.”
Rain will continue tonight, becoming heavy at times, however, it will gradually ease over but strong winds will persist.
New Year's Eve will be a windy day with fresh to strong gusty and southwesterly winds, reaching near gale force at times, before easing light to moderate towards evening.
“It will become windy again on Friday night as southerly winds increase fresh to strong and gusty,” Met Éireann said.
"Spells of rain will spread from the southwest through the night. Mild with lowest temperatures of 9 to 11 degrees.”
New Year’s Day will be quite wet and blustery, and it will be milder than average for the beginning of January with highest temperatures of 11 to 13 degrees.
There will be heavy showers on Saturday night which will become lighter over night, however, there will be more widespread showers on Sunday morning.
"There will be a good deal of cloud around but some sunny spells will break through in the afternoon,” a Met Éireann forecaster said.
"Temperatures starting to return closer to normal with highest temperatures of 8 to 10 degrees in moderate southwesterly winds.”
Sunday night will see a mix of clear spells and scattered showers with further showers and sunny spells forecast for Monday morning.
From beyond Monday the national forecaster said current indications suggest it will turn colder towards midweek but drier overall.