A status yellow rainfall warning is in place for five counties in Leinster and will remain in effect until tomorrow evening.
The counties affected are Dublin, Kildare, Louth, Wicklow and Meath.
The alert, which came into effect at 6pm today, warns of spells of heavy rain and some spot flooding.
It will remain in place until 9pm tomorrow.
Matthew Martin of Met Éireann said a low pressure system moving over the Irish Sea will feed into some heavy showers.
"It's quite similar to the event we had on Monday of this week," he said, bringing with it the risk of spot flooding.
It is estimated that between 20mm and 30mm of rain will fall in the Greater Dublin Area.
The wind over the Irish Sea at this time of year is the reason for the east being affected, in particular, explained Mr Martin.
It comes after some 50mm of rain fell over the weekend, affecting the water supply to parts of Kildare, Dublin and Meath.