Met Éireann has issued a Status Yellow rain and wind warning for Dublin and Wicklow.
The warning comes into effect at midday tomorrow, valid until 8pm.
The forecaster said rain, heavy at times, coupled with gusty winds will be strongest near the coasts and on higher ground.
It warned that spot flooding and traffic disruption is possible.
Elsewhere, a Yellow rain warning has also been issued for counties Antrim, Armagh and Down.
The UK Met Office said heavy rain may lead to some flooding and transport disruption in places.
Its warning is due to come into effect at 8pm tonight until midday tomorrow.