A status yellow rain warning has been issued for 15 counties leading to further fears of flooding in the midlands and west.
Met Eireann says up to 25 millimetres of rain could fall between Sunday night at 8pm and Monday morning.
Many areas along the River Shannon are on alert, with much farmland already under water.
Water levels on the Shannon in Athlone are continuing to rise.
In the latest update, Westmeath County Council says the levels have reached 39.00 meters relative to the Poolbeg datum
As expected at these river levels, there is water on the minor roads in the lower parts of the town.
There are no residences at imminent risk and water levels remain approximately 0.8m below the highest level recorded in Winter of 2015/16.
Westmeath County Council staff are on the ground carrying out protective works and will continue to deploy defence measures as required and in the expectation that water levels will continue to increase in the coming days.
Minister for Flood Relief Kevin ‘Boxer’ Moran says people are worried.