Met Eireann has issued a 24-hour rainfall warning.
The yellow alert which started at 9am affects counties Carlow, Kilkenny, Wexford, Cork, Kerry, Tipperary and Waterford.
Up to 35 milimeters of rain are expected to fall - turning heaviest on high ground.
The Taoiseach will meet with Ministers today to discuss the impact of storm Frank - there will also be a briefing from the Government's flood taskforce.
Jim Casey from the Office of Public Works is warning that the River Shannon is continuing to rise: