Ireland is to see back-to-back days of 22C temperatures on Thursday and Friday.
However, Met Eireann says all parts of the country will experience rain at times.
Highest temperatures are to be lower over the bank holiday weekend, with heavy showers and highs of just 19C on Saturday afternoon.
Sunday and Monday aren't expected to be any warmer - but the weather chiefs are forecasting better conditions with good sunny spells despite the odd shower.
A Met Eireann spokesman said: "Sunday will be a bright day with sunshine and showers.
"Highest temperatures of 15 to 19 degrees with moderate southwest breezes.
"There is a possibility of persistent rain in the south for a time on Sunday night.
"Monday will be bright with good sunny spells. There'll be a few showers in Connacht and Ulster, but many areas will stay dry.
"Highest temperatures of 15 to 19 degrees with light westerly or variable breezes."
Meanwhile, Thursday is set to be warm and humid with highs of 22C.
There may be heavy rain at times early on but any downpours will clear northwards in the afternoon.
The spokesman said: "Outbreaks of rain this morning, heavy at times, especially in Connacht and Ulster.
"Drier weather will follow from the south and the rain will clear northwards this afternoon.
"Some sunny breaks will develop. Warm and humid with highest temperatures of 18 to 22 degrees, and moderate to fresh southerly winds, strong at times on the west coast."
