A rainfall warning for counties Wexford, Cork and Waterford comes into effect from 3pm today, with heavy rains expected to bring spot flooding to these areas.
The status yellow warning is to stay in place until midnight on Wednesday.
Met Éireann said rains of up to 30mm could be expected in places in the three counties.
The forecaster also said the highest temperatures in northern counties on Tuesday would be between 2 to 5 degrees Celsius, but southern counties could expect peaks of between 6 to 9 degrees.
Overnight, rain in the south and west of the country will gradually spread to all areas, with fresh or moderate winds expected.
Overnight temperatures will be between -1 and 3 degrees in northern counties, and between 3 and 8 degrees elsewhere.