A status orange weather warning for thunderstorms remains in place for the Republic until 9am on Monday.
Met Éireann is warning of sporadic thunder and lightning across south Leinster and Munster.
Met Éireann forecaster Andrew Doran-Sherlock said a heat warning also remains in place for Leinster, Munster, Cavan, Monaghan, Munster, Galway and Roscommon.
— Met Éireann (@MetEireann) August 14, 2022
Mr Doran-Sherlock told Newstalk: "It's partially this heat that is contributing to thunderstorms, so it will still be an uncomfortably warm night tonight in many areas, but there are fresher conditions feeding in from the northwest through today which is why they're no longer in the high temperature warning.
"Through tomorrow, and next week, we will see temperatures falling to more normal levels for the time of year."
Met Éireann said Monday would see scattered showers and thunderstorms continue to affect the southern half of the country, becoming intense through the afternoon with the continued risk of flooding.
It will be fresher, but drier further north with just isolated showers and intermittent sunny spells.
Ireland's all-time temperature record for August was broken on Friday, as Oak Park, Co Carlow reached 31.7 degrees.
The previous record was set by both Ballybrittas, Co Laois in 1975, and by Oak Park itself in 1995.
A heatwave was officially declared in Ireland on Sunday.
It comes after temperatures exceeded 25 degrees for the fifth day in a row, with Moore Park in Cork, recording 28.8 degrees on Saturday.