Met Éireann has issued a Status Yellow rain warning.
The warning will be in effect from 5:00p.m on Monday (August 3) until midnight.
The warning is in place for counties Wexford and Wicklow.
Met Éireann said spells of heavy thundery rain can be expected.
Potential impacts include spot flooding and difficult travel conditions.
Across the country today there will be a mix of cloud and bright or sunny spells for a time, with scattered showers.
It will become mostly cloudy later with showers or longer spells of rain pushing up from the south this afternoon and evening.
Some heavy, potentially thundery downpours are possible, bringing a risk of spot flooding, especially in the south-east.
It will be humid with highest temperatures of 19° to 24° in light to moderate easterly winds becoming mainly south-east this afternoon.
It will be mostly cloudy with limited clear spells tonight.
Heavy rain or showers will continue to extend north-eastwards over the country, bringing a continued risk of spot flooding.
The showers will gradually ease in most places later in the night.
It will be another mild and humid night with lowest temperatures of 12° to 16° in light southerly breezes.
After a mostly cloudy and misty start to Tuesday, with patchy rain and drizzle in parts, sunny spells will gradually develop along with scattered showers.
Some of the showers will be heavy and thundery, especially over parts of Connacht and Ulster.
It will continue humid with highest temperatures of 18° to 23°, coolest in the north-west, with light to moderate south-west to west winds.
It will be a a mixed and unsettled week ahead. It will be rather humid at first but turning cooler from midweek.