Temperatures are expected to hit 26 degrees this weekend as a warm front that has brought scorching temperatures to the UK sweeps over Ireland.
On Saturday, temperatures are forecast to reach 24 degrees before it becomes even warmer on Sunday, particularly in Leinster and the midlands, with highs of 26 degrees expected.
Sunday night looks set to be mild, humid and mostly dry with some showers in east Leinster and parts of Ulster.
Monday will begin dry over most of Munster and Connacht. The afternoon will see heavy and thundery showers that will travel from the east and affect most of Leinster and Ulster. However, it will remain warm with temperatures of 24 degrees.
A thunderstorm warning is set to come into force on Monday for counties Antrim, Armagh, Down, Fermanagh, Tyrone and Derry.
The middle of next week looks set to continue warm, with temperatures of 18 to 24 degrees on Tuesday and Wednesday, while Thursday is also set to be dry.
In the UK, temperatures soared again on Saturday after Friday saw the hottest August day in 17 years, with 36.4 degrees reported at Heathrow and Kew Gardens.
The Met Office said temperatures had already reached 34.5 degrees at Frittenden in Kent early on Saturday.
Saturday started with an "impressive" 20 degree difference between parts of Scotland and south-east England, the Met Office pointed out.
Forecaster Marco Petagna earlier said a breeze along the North Sea coast would keep temperatures in the high teens there, while England and Wales would generally see the high 20s or low 30s - with cooler temperatures in Scotland and Northern Ireland.
London and the south east have endured sweltering heat over the past few days, with no let-up expected until the middle of next week.
The record for the hottest August day is 38.5 degrees, set at Faversham on August 10 2003.
The current record maximum temperature for the UK is 38.7 degrees, reached in Cambridge Botanic Garden on July 25th last year.
The Met Office has issued a level three heat-health warning for the south and south east, meaning the public should look out for others, particularly the elderly, children and people in poor health.
UK, since although the ingredients are there, it’s just too early to pinpoint the details of exactly where and when thunderstorms will occur,” he said.
“As such, we will be monitoring the developing signals closely and I urge people to keep a close eye on Met Office warnings and forecasts over the coming days.”