Fifteen counties will be affected by a rainfall and thunderstorm warning later today.
The status yellow alert covers all of Leinster, along with Cavan, Monaghan and Tipperary.
It will run from 2 o'clock this afternoon until 10 o'clock tonight.
Met Eireann's warning of heavy showers, isolated thunderstorms and localised flooding.
But temperatures could reach the high-20s later this week, according to the forecaster.
It's predicting warm temperatures from Wednesday, reaching 25 degrees on Friday, and continuing to be very warm for the weekend.
"Well, after a fairly dismal weekend in places, the news is good for this week," says forecaster Evelyn Cusack.
"It's going to turn into an overall dry, warm and sunny week. Next weekend will be very warm, with temperatures in the mid to high-20s.
"Today and tonight will be dull and misty, especially over Leinster - with heavy showers and a risk of thunderstorms, but then it's really good weather."