Portmarnock had a taste of this week's heatwave yesterday when the mercury soared.
"It's possible we'll get 30C or more," forecaster Deirdre Lowe said of the peak temperatures expected by Friday.
For the first time in recent memory, nights will remain warm, with the mercury hovering in the mid to high teens.
The Mediterranean-style nights are expected to kick in today or tomorrow.
While some temperature records are likely be broken this week, it is unlikely they will match the blistering 33.3C recorded in Co Kilkenny in 1887.