Met Éireann has issued a Status Yellow rainfall warning for 10 counties for tomorrow, Friday, July 19.
Issued today, the warning will be valid from 8:00am tomorrow morning through to 8:00pm in the evening.
The alert is in place for counties: Galway: Mayo; Roscommon; Sligo; Leitrim; Donegal; Cavan; Monaghan; Longford; and Westmeath.
Today, there will be scattered showers with some sunny spells today and showers will turn heavy mainly over the northern half of the country.
Top temperatures will reach 17° to 21° in moderate westerly breezes, occasionally fresh along Atlantic coasts.
Tonight, showers will become isolated in the north and it will be dry for a time but cloud will increase from the southwest with rain soon pushing in over Munster and spreading to Leinster and Connacht by dawn.
Lowest temperatures will drop to 10° to 14° in light south-west to southerly breezes, according to Met Éireann.
Tomorrow morning will see rain become widespread and heavy and turn more showery later with the risk of thundery downpours, which may lead to localised flooding.
However, winds will increase to fresh and gusty southwesterly over Munster and Leinster during the afternoon.