Beach Safety
Box Jellyfish Calendar.
Hawaiian box jellies (Alatina alata) arrive on Waikīkī's south shore in predictable waves, about 8 to 10 days after each full moon.
What & why
Why a calendar?
Each lunar cycle, mature box jellies move into shallow waters along Oʻahu's leeward south shore to spawn. The pattern is so reliable that lifeguards and ocean users plan around it.
Stings are painful and occasionally serious. Use this calendar alongside posted lifeguard warnings.
Full Moon
Likely Influx Window
Jan 13, 2025
Jan 21 – Jan 23
Feb 12, 2025
Feb 20 – Feb 22
Mar 14, 2025
Mar 22 – Mar 24
Apr 12, 2025
Apr 20 – Apr 22
May 12, 2025
May 20 – May 22
Jun 11, 2025
Jun 19 – Jun 21
Jul 10, 2025
Jul 18 – Jul 20
Aug 9, 2025
Aug 17 – Aug 19
Sep 7, 2025
Sep 15 – Sep 17
Oct 6, 2025
Oct 14 – Oct 16
Nov 5, 2025
Nov 13 – Nov 15
Dec 4, 2025
Dec 12 – Dec 14
If you're stung
First aid basics
- Leave the water calmly, additional stings can occur if you panic.
- Rinse the area with vinegar for at least 30 seconds to deactivate undischarged stinging cells.
- Remove tentacles with tweezers or a gloved hand. Do not rub.
- Apply heat (hot water as tolerated, ~45°C/113°F) for 20–45 minutes to ease pain.
- Seek medical care if you experience difficulty breathing, chest pain, or a severe reaction.
Disclaimer
Always check local warnings
This calendar is a guide, not a guarantee. Influx timing varies by site, weather and ocean conditions. Always heed posted warnings from Honolulu Ocean Safety lifeguards.