Check the water before you enter is the message for Aucklanders, as stinging jellyfish wash ashore.
Auckland Council is urging the public to be cautious following reports of numerous lion's mane jellyfish, up to 8cm in diameter, being spotted on east coast beaches.
"The lion's mane jellyfish that have been washing up at different times and locations on east coast beaches, Waiheke and Great Barrier islands are not poisonous, however the public should avoid them when swimming due to their sting," said council regional environmental control manager Marcus Herrmann.
"In some cases they have been pushed into harbours and inlets in sizeable amounts - it's best to find an alternative swimming location on those days."
Warm weather and onshore winds can bring jellyfish into beaches, which can appear at any Hauraki Gulf beach at any time.