Met Éireann has issued a status yellow weather warning for Thursday 9 September.
The heavy rain and thunderstorm warning is in place for Leinster, Cavan, Donegal, Monaghan, Connacht, Tipperary and Waterford.
The heavy and potentially thundery downpours will cause some localised flooding and will break through on Thursday afternoon, clearing later in the evening.
The surface water and spot flooding might cause disruption to travel in some parts of the country.
Motorists have been advised to drive with care.
The downpours are expected to clear by late evening at approximately 10pm.
A status yellow warning is also in place in Northern Ireland for Antrim, Armagh, Down, Fermanagh, Tyrone and Derry.