The west is set to be worst hit as the country is subjected to a status yellow warning for wind and rain on Wednesday.
The warning came into effect at 4am and will remain in place until 9pm.
Met Éireann is warning of possible damaging gusts with the potential for "localised wave overtopping along Atlantic coasts".
The warning may also be raised to an orange alert in Donegal.
Alan O'Reilly from Carlow Weather said heavy downpours could cause flooding.
Mr O'Reilly told Newstalk: "We will also see some very heavy rain with a possible squall line moving through, which will see very heavy downpours for a short period of time.
"And along with those downpours will be a sudden increase in gusts. Given how much rainfall we've had in recent weeks, certainly water levels are very high so any further heavy downpours will result in some local spot flooding."
