Habu-kurage box jellyfish season
ハブクラゲ発生注意報SeasonJune, July, August, September
Okinawa Prefecture's habu-kurage warning runs from 1 June to 30 September, the months when this venomous box jellyfish stings the most swimmers. In 2025 habu-kurage caused 81 of the 199 stings and bites by dangerous sea creatures reported in the prefecture.
Okinawa Prefecture says the habu-kurage (ハブクラゲ) grows fast from about early June to a size that can harm people, just as the beaches fill with swimmers. The prefecture issues its warning for June to September every year, and in 2026 it ran from 1 June to 30 September. Of the 199 stings and bites by dangerous sea creatures reported in 2025, 81 (about 40.7%) came from habu-kurage.
Swim inside the jellyfish nets where a beach has them, and take a bottle of ordinary vinegar to the beach. The prefecture also asks swimmers to keep as much skin covered as they can. If someone is stung, get them out of the water calmly and call for help, pour plenty of vinegar over the sting without rubbing it, then lift off the tentacles and cool the skin with ice or cold water before heading to a clinic.
On Miyako the tourism association warns that habu-kurage can drift in on windy summer days and that few of the island's beaches have lifeguards.
Worth knowing
- The prefecture's hygiene and environment research institute posts the list of beaches with jellyfish nets.
FAQ
Quick answers about Habu-kurage box jellyfish seasonよくある質問
When is jellyfish season in Okinawa?
Jellyfish season in Okinawa runs from June to September, when Okinawa Prefecture issues its yearly habu-kurage warning. The 2026 warning covered 1 June to 30 September.
What should you do if a habu-kurage stings you?
Get out of the water calmly and pour plenty of vinegar over the sting without rubbing it, Okinawa Prefecture advises. Once the tentacles are off, cool the skin with ice or cold water and see a doctor.
Are there jellyfish nets at Okinawa beaches?
Yes. Some Okinawa beaches put up habu-kurage nets, and Okinawa Prefecture asks swimmers to stay inside them. The prefecture's hygiene and environment research institute publishes the list of netted beaches.