There has been some flooding at high tide in low-lying areas of Cork city centre.
Cork City Council had issued a warning earlier that there was "a significant risk" of flooding in the city this evening.
It said a very high spring tide is coinciding with a tidal surge and periodic strong southerly or southeasterly winds.
Householders and businesses were advised to "take precautionary measures to protect their property".
The worst affected areas were at Morrison's Island, Union Quay and Lavitts Quay. The South Terrace was also been reduced to one lane, as a result of flooding.
However, Cork City Council said there have been no reports of any damage to homes or businesses.
Director of Operational Services at Cork City Council, David Joyce, said: "We are well prepared to support the citizens and businesses of Cork during this unusual August tidal event."
He said the city's Flood Response Plan has been activated and the council, fire services, gardaí and Civil Defence had been on standby in case of problems.