Met Éireann has issued a Status Yellow Rainfall warning.
The alert - is valid for Mayo, Galway, Sligo, Leitrim, Roscommon, Donegal, Clare, Kerry and Limerick at 2pm this afternoon - will remain in place until 9pm.
"Heavy thundery downpours this afternoon and evening will lead to flash flooding and hazardous driving conditions." Met Éireann warned.
"Intense rainfall amounts of 20 to 30 mm in a short period of time likely."