Householders and motorists have been warned to expect flash flooding during heavy rainfall along the east of the country.
Met Eireann has forecast some 25mm of rain could fall over a 12 hour period from 9am on Wednesday.
AA Roadwatch said heavy rain has already resulted in some spot flooding in southern areas.
"Further showers are expected to spread eastwards into tonight and tomorrow," it said. "Only drive through water if you know it's not too deep for your car."
Dublin City Council said while the predicted amount of rainfall is considerably less than what caused extensive flooding last October, it would monitor the situation and liaise with Met Eireann and the emergency services.
Hundreds of homes and cars were flooded and two people died when almost 100mm of rain fell over 24 hours last autumn.
"The city council has also placed resources on standby to attend to flood locations that may arise," it said.
"Gullies and river screens in flood prone areas are being cleaned and monitored during the warning period.
"The city council will have a stock of sandbags placed on standby for strategic deployment. Owners of premises that consider themselves at risk of flooding are also advised to make provision to defend their own premises."
It said extreme rainfall events, because of their nature, are unpredictable in behaviour and as such pose flood threats to premises in all parts of the city. It added: "While there is no threat of tidal flooding the city council, as an additional reassurance to residents in the lower Dodder area, will close the tidal gates at this location."