Swimming has been banned in popular tourist destinations, including Lahinch and Kilkee after the waters tested for high levels of bacteria following heavy rain in the area.
Clare County Council had previously advised visitors not to swim in the two beaches, as well as White Strand, Spanish Point and Quilty, but upgraded the warning to a swimming ban following consultation with the HSE.
In March, gardaí were forced to turn people away from the beach at Lahinch as large crowds gathered there to enjoy the warm weather despite social distancing guidelines.
Elsewhere, people are being urged to take care in the water as Irish Water Safety has warned that the moon will have a big affect tides this weekend.
CEO John Leech says people should only swim in areas where there are on-duty lifeguards and not use floatable devices in open water.
"On Monday there is a full moon and what that does is bring a spring tide around our coast line. We will have much stronger rip currents and tidal streams operating, so people can get pulled out from a beach very easily if they are not aware of where the rip currents are."
