Met Eireann have warned of changeable conditions ahead as the week will start off dry and warm but become more unsettled with a risk of rain.
Today will see highs of 18C in some areas but it will be cloudy and much cooler in parts of the country.
A forecaster said: "Sunday will be cool and cloudy across the north and west with scattered outbreaks of rain and drizzle.
"Over Munster and south Leinster rain and drizzle will be patchier in nature and mixed with some sunny spells. Highs of 10C to 12C in north Leinster, Connacht and Ulster, 13C to 18C elsewhere."
The pattern will be repeated on Monday, with highs of 10C to 14C in the north and west but rising to 15C to 20C elsewhere.
Monday will be mostly cloudy, with patches of rain and drizzle merging to give longer spells of rain later in the day mainly in the north and west.
The east coast and Munster, however, will see some bright spells.
Heading into Tuesday, it looks more promising as temperatures are set to hit highs of 21C.
The day will start off cloudy at first, with patchy rain and drizzle, mainly in the west, north and on the east coast but it will become mostly dry during the day, with bright or sunny spells developing, especially in the midlands and east.
Met Eireann say it will be "quite warm", with maximum temperatures of 17C to 21C, but cooler on southern and Atlantic coasts, in light to moderate southwesterly breezes.
But a forecaster cautioned that we'll see a big shift in the weather later this week.
They said: "The weather will be changeable for the rest of the week with a good deal of dry warm weather but early indications are for more unsettled weather with rain chances increasing for the second half of the week."
