All but five of Met Éireann's stations around the country have seen record levels of rainfall for December.
Twenty stations have seen record levels, with Valencia station experiencing its highest level of rainfall in 76 years.
Many areas around the country have been hit by heavy flooding and water levels on the River Shannon at Athlone have matched those reached in 2009.
Head of forecasting with Met Éireann Gerald Fleming said we have more heavy rain on the way tomorrow.
"There is another weather system coming in for tomorrow evening through the late hours of Friday and into Saturday morning," he said, "and another one following on Sunday, so we have two more belts of rain coming over the weekend.
"They will mainly impact the south and south-west, and in total will probably bring another 20mm to 25mm to parts of Cork and Kerry and maybe up into Clare, Limerick and Galway."
Meanwhile, Brendan Lawlor from the HSE warned those affected by flooding to remember that flood water may cause sickness.
"We need to be mindful of how we approach flood waters, and treat all such waters as contaminated," he said.
"Keep yourself well protected from the water. If you are in contact with the water, wash afterwards in clean, soapy water or use alcohol wipes."