Jellyfish at Nai Harn Beach

หาดในหาน · Phuket · Andaman Sea

Risk today · 25 Oct 2026Low

Main factor: Calm water and rain

No jellyfish reports; conditions are typical for the season.

Today the jellyfish risk at Nai Harn Beach is low. Main factor: calm water and rain. In October it is usually moderate here. It is an estimate, not a guarantee: follow beach flags and lifeguards.

What to expect today

5-day outlook

  1. TodayLow4 m/s NW — Wind: up to 4 m/s, blowing from NW. The arrow shows where it blows to. Onshore wind pushes jellyfish to the beach.0.8 m — Waves: up to 0.8 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.20 mm — Rain: 20 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  2. TomorrowLow3 m/s W — Wind: up to 3 m/s, blowing from W. The arrow shows where it blows to. Onshore wind pushes jellyfish to the beach.1.0 m — Waves: up to 1.0 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.22 mm — Rain: 22 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  3. Tue 27Low3 m/s SW — Wind: up to 3 m/s, blowing from SW. The arrow shows where it blows to. Onshore wind pushes jellyfish to the beach.0.9 m — Waves: up to 0.9 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.23 mm — Rain: 23 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  4. Wed 28Moderate4 m/s S — Wind: up to 4 m/s, blowing from S. The arrow shows where it blows to. Onshore wind pushes jellyfish to the beach.0.5 m — Waves: up to 0.5 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.33 mm — Rain: 33 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  5. Thu 29Low4 m/s SE — Wind: up to 4 m/s, blowing from SE. The arrow shows where it blows to. Onshore wind pushes jellyfish to the beach.0.5 m — Waves: up to 0.5 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.37 mm — Rain: 37 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  6. Fri 30Moderate5 m/s SE — Wind: up to 5 m/s, blowing from SE. The arrow shows where it blows to. Onshore wind pushes jellyfish to the beach.0.5 m — Waves: up to 0.5 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.23 mm — Rain: 23 mm in the day. Box jellyfish are more common near river mouths after heavy rain.

Why this level

  • Box jellyfish Lowusual background
    calm water and rain, usual for the season
  • Other jellyfish and stinging plankton Lowusual background
    jellyfish season in this area, usual for the season
  • Bluebottles (Portuguese man o’ war) Lowlowers risk
    below usual for the season

It is not jellyfish season on Phuket's west coast, the wind is light or along the shore, moderate waves (~0.8 m), so the risk level is low. There are no recent jellyfish reports.

Recent reports

No recent reports.

Report jellyfish

At this beach now? Your report helps others. "No jellyfish today" is useful too.

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Seasonality

Bars show the baseline seasonal risk for this coast; dots show official warnings nearby by month.

Nai Harn: jellyfish month by month

  1. January: Usually moderate risk. High risk on 7% of days. Onshore wind on 0% of days. Official warnings: 0. Eyewitness reports: 76.
  2. February: Usually moderate risk. High risk on 12% of days. Onshore wind on 3% of days. Official warnings: 0. Eyewitness reports: 39.
  3. March: Usually moderate risk. High risk on 6% of days. Onshore wind on 15% of days. Official warnings: 2. Eyewitness reports: 29.
  4. April: Usually moderate risk. High risk on 6% of days. Onshore wind on 53% of days. Official warnings: 0. Eyewitness reports: 22.
  5. May: Usually moderate risk. High risk on 35% of days. Onshore wind on 73% of days. Official warnings: 2. Eyewitness reports: 14.
  6. June: Usually moderate risk. High risk on 32% of days. Onshore wind on 99% of days. Official warnings: 3. Eyewitness reports: 21.
  7. July: Usually moderate risk. High risk on 10% of days. Onshore wind on 98% of days. Official warnings: 2. Eyewitness reports: 7.
  8. August: Usually moderate risk. High risk on 17% of days. Onshore wind on 100% of days. Official warnings: 1. Eyewitness reports: 5.
  9. September: Usually moderate risk. High risk on 11% of days. Onshore wind on 95% of days. Official warnings: 1. Eyewitness reports: 11.
  10. October: Usually moderate risk. High risk on 8% of days. Onshore wind on 71% of days. Official warnings: 0. Eyewitness reports: 2.
  11. November: Usually low risk. High risk on 0% of days. Onshore wind on 25% of days. Official warnings: 0. Eyewitness reports: 6.
  12. December: Usually moderate risk. High risk on 1% of days. Onshore wind on 0% of days. Official warnings: 1. Eyewitness reports: 18.
  • Low
  • Moderate
  • High
  • Very high

Colour shows the typical risk level that month; the number is the share of high-risk days. Warnings and sightings are in each month’s tooltip.

Coordinates: 7.7756, 98.3046

Questions and answers

Can I swim at Nai Harn Beach today?

Today's estimated risk is low; main factor: calm water and rain. It is an estimate, not a guarantee: "no reports" does not mean there are no jellyfish. Check beach flags and follow lifeguards.

Have jellyfish been seen at Nai Harn Beach recently?

No reports in the last 14 days. It is an estimate, not a guarantee: "no reports" does not mean there are no jellyfish. Check beach flags and follow lifeguards.

In which months are jellyfish more likely at Nai Harn Beach?

Based on 2022–2026 weather, the risk is most often elevated in May, June, July. Official warnings nearby: 12.

Who do I call after a jellyfish sting?

Emergency medical services in Thailand: 1669 (free). Alert the beach lifeguard; if a box jellyfish is possible, pour vinegar over the sting for at least 30 seconds.