The city has posted jellyfish warning signs at Waikiki beach and Hanauma Bay Nature Preserve.

Waikiki lifeguards reported 40 stings and counted roughly 200 jellyfish this morning, while lifeguards at Hanauma Bay reported three stings and counted roughly five jellyfish.

Box jellyfish usually appear from eight to 10 days after a full moon, according to the Waikiki Aquarium, which offers a box jellyfish calendar online.