The country got a taste of the Mediterranean at the weekend with some of the highest temperatures and best sunshine this year.
Next weekend also looks "promising", according to forecasters.
Last Friday and Saturday were the best days with a high of 27.6 degrees recorded for the mid-west at Shannon Airport on Saturday.
Temperatures ranged from 20 to 25 degrees during the weekend, with the best of the sunshine on Saturday.
Sunday was also warm, with the west, particularly west Kerry and Connacht, getting the best of it with temperatures of 23 and 24 degrees.
The east and north-east were cooler, with patches of thicker cloud in the morning and early afternoon, but most of these broke by mid-afternoon giving good sunny spells.
The warm, humid weather is likely to continue throughout the earlier part of this week, though showers are expected by Thursday and Friday.
Dry, sunny weather is expected throughout the country today but with some risk of showers in the south by mid-afternoon. It will be cooler on the coast.
It will then warm up again, with temperatures tomorrow and Wednesday expected to reach highs of 25 and 26 degrees. However, cloudier weather will then to move in.
Occasional bright, sunny spells should still break through, but they will be less frequent.
The risk of showers is due to increase as the week progresses. Met Eireann predicts that the dry weather is "almost certain to break" by Thursday, and there will be an increasing threat of heavy local downpours set off by the heat.
This heavy rain is most likely to hit the midlands, where the temperatures have been highest, but showers will affect the whole country.
It will remain warm, with temperatures of 23 and 24 degrees inland and 18 degrees in coastal areas.
The outlook for the weekend is "promising" with a return to drier weather expected.
"Temperatures should be back up to at least the early 20s by next weekend," Met Eireann said.
The current spell of weather is the hottest continuous spell this year, although a high of 27.6 degrees was recorded on June 18th.
Met Eireann said temperatures had been "slightly above normal for the time of year", although June was a particularly cloudy month.
