A series of rainfall warnings are in place along the west and south west with a forecast of up to 100mm possible in mountainous and a localised risk of flooding.
An orange rainfall alert, the second highest possible, has been issued for Co Kerry where 60mm to 80mm of rainfall is forecast today with up to 100mm possible in mountainous areas.
A less severe yellow rainfall alert is in place for counties Galway, Mayo, Clare and Cork where rainfall of between 30mm to 50mm are forecast.
The rainfall alerts are until 6pm on Tuesday.
The Road Safety Authority (RSA) has advised all road users to take extreme care tonight and tomorrow as accumulations of 30 to 50 mm of rain are expected in places.
The RSA has reminded drivers to slow down and allow extra distance between you and the vehicle in front when conditions are wet.
According to Met Éireann the rest of the country will be "mainly dry with a few bright or sunny spells" with blustery, southeasterly winds.
This evening will be wet in western coastal counties with some heavy falls leading possibly to localised flooding, the forecaster said.
On Tuesday more heavy rain is forecast for western and south western coastal counties.
For the rest of the week, the outlook is more positive, with Wednesday mostly dry and bright while Thursday and Friday should be generally fine.