Forecasters have issued a severe weather warning for today, but some semblance of summer will arrive midweek - just in time for the State exams.
Forecasters agree that temperatures are finally set to rise later this week, after a horrible May in most parts of the country.
But the first day of the Irish summer today will see more of that same dreadful weather - with an Orange Alert wind warning for Leinster and a Yellow Alert for the rest of the country. Winds gusting to 115kmph will hit the east of the country from this morning.
Met Eireann meteorologist Siobhan Ryan said a complex weather system will bring rain, hail and high winds to the whole country today, with Tuesday another 'washout'.
Warmer weather from continental Europe will begin to arrive over the country on Wednesday - just as thousands of students begin Junior and Leaving Cert exams.
Thursday will see warm and dry weather with temperatures up to 20C or 21C, with the best of the weather in the south and east.
Temperatures could hit 28C in southern England this week.
But for Ireland, two new weather systems will go into battle by the weekend, which could see either hot weather or a series of thunderstorms.
She said there was still a great deal of uncertainty over Friday, with a wet Atlantic front vying for dominance over the warm ridge of high pressure from Europe.
This could, she said, lead to heavy thunderstorms.
"There is a lot of uncertainty about the end of the week with a battle ground between an Atlantic regime and warm continental air but there is likelihood at this stage is for rain despite some very good temperatures," said Ms Ryan.
She said temperatures over the past week had been 2.5C below average for the time of the year in the west of the country and 1.5C cooler in the east.
It was also duller, with Ulster and Connacht seeing just 70pc of normal sunshine hours.
Only the south-east saw below average rainfall, with up to 150pc across northern areas.
Cork has had the best of the weather with just 8mm of rain in the past seven days. Higher temperatures there also helped grass growth for farmers.