Flood warnings have been issued by both Galway and Cork City Councils.
Cork City Council says a predicted storm surge coinciding with the astronomical high tide may give rise to flooding on some streets in the city.
High tide is predicted at 5.53am tomorrow morning, and at 6.17pm tomorrow evening.
Met Éireann is also warning of a risk of localised flooding, especially in the south, overnight and tomorrow.
The areas most at risk from tidal flooding are Morrisons Quay, Sharman Crawford Street, and Wandesford Quay.
Householders and businesses are being urged to take steps to protect their properties.
Galway City Council also issued a warning about potential flooding from high tide at 5pm today until 7pm on Friday 10 October.
High tide this evening passed without any major problems.
There has been a small amount of "topping" at the Spanish Arch in the city centre, after the Corrib breached the river bank.
But water has not extended past a temporary safety barrier, erected by council officials around a metre back from the bank.
The local authority has issued a warning regarding the potential for flooding for the rest of the week, during high tides.
There is particular concern about the problems that could arise through a combination of high tides and forecasted weather conditions tomorrow evening and on Thursday.
Businesses and homes in affected areas around the city and in Salthill are being advised to take precautionary measures.
Sandbags are being made available and council officials are on standby to deal with any problems that may arise.
Storms and high tides combined to devastating effect in Galway earlier this year, when hundreds of thousands of euro worth of damage was caused to public thoroughfares.
Businesses and homeowners sustained millions of euro worth of damage.
The clean-up operation from those storms is continuing, ten months later.
Work on restoring the council administered Leisureland facility is ongoing, after over €500,000 worth of damage to the swimming pool and gym area there.