The weather is to remain unsettled and changeable for the weekend and into next week, Met Eireann says.
Today (Friday) will be cloudy with outbreaks of rain and drizzle spreading eastwards, turning more persistent in the west and north by mid-morning.
There will be heavy falls of rain and a risk of thunder in Ulster and Connacht in the afternoon, Met Eireann says.
Rain will become widespread in the afternoon and evening, it says, while it will be another cool day with temperatures only reaching 14 to 16 degrees.
Tonight (Friday) persistent and locally heavy rain will affect eastern and southern areas at first. There will be isolated showers mainly in coastal areas but it will become mostly dry with clear spells elsewhere.
Tomorrow (Saturday), Met Eireann says that the southern half of the country will see a mostly dry start with some sunny spells, but cloud will increase from the south with patchy rain or drizzle developing in southern coastal counties in the afternoon.
However, it says across the northern half of the country it will be a wet and cloudy day from the start with scattered showers becoming widespread in the afternoon, with some heavy falls in places.
There will be highs of 14 to 18 degrees on Saturday and it will be coolest in the north in moderate to fresh southwesterly or westerly winds, it says.
Saturday night will be cloudy with rain developing in the west and spreading eastwards through the night, the rain will be heaviest for western coastal counties, it says.
There will be lows of 9 to 12 degrees on Saturday night, Met Eireann says in light to moderate, locally fresh, southwest winds.
However there will be some dry intervals in the east, but cloudy with outbreaks of rain or drizzle there too, it says.
There will be highest temperatures of 14 to 18 degrees, coolest over Ulster and becoming windy as southeast winds will increase fresh to strong and gusty, it says.
Met Eireann says that winds will increase on Bank Holiday Monday due to a nearby Atlantic depression, which is likely to bring strong gale force southerly winds.
It says there is potential for heavy showers especially in the west however parts of the east could see more dry intervals.
The southerly winds will bring a milder airmass, Met Eireann says, and with a chance of some sunny spells in between showers it will become a little warmer with highs of 16 to 19 degrees.
The outlook for next week is that the weather is to remain unsettled for the rest of the week.
There will be scattered showers on Tuesday, isolated showers on Wednesday and rain will push across the country from the south on Thursday, according to Met Eireann.