Jellyfish at Long Beach (Hat Sai Yao, Koh Chang)

หาดทรายยาว · Koh Chang · Gulf of Thailand

Risk today · 24 Oct 2026Moderate

Main factor: Stronger wind than usual

Conditions or reports nearby make an encounter more likely.

Today the jellyfish risk at Long Beach (Hat Sai Yao, Koh Chang) Beach is moderate. Main factor: stronger wind than usual. 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. TodayModerate4 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.0.1 m — Waves: up to 0.1 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.7 mm — Rain: 7 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  2. TomorrowModerate4 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.0.2 m — Waves: up to 0.2 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.2 mm — Rain: 2 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  3. Mon 26Moderate4 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.0.3 m — Waves: up to 0.3 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.3 mm — Rain: 3 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  4. Tue 27Moderate2 m/s N — Wind: up to 2 m/s, blowing from N. The arrow shows where it blows to. Onshore wind pushes jellyfish to the beach.0.3 m — Waves: up to 0.3 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.0 mm — Rain: 0 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  5. Wed 28Moderate3 m/s N — Wind: up to 3 m/s, blowing from N. The arrow shows where it blows to. Onshore wind pushes jellyfish to the beach.0.2 m — Waves: up to 0.2 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.2 mm — Rain: 2 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  6. Thu 29Moderate2 m/s S — Wind: up to 2 m/s, blowing from S. The arrow shows where it blows to. Onshore wind pushes jellyfish to the beach.0.1 m — Waves: up to 0.1 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.14 mm — Rain: 14 mm in the day. Box jellyfish are more common near river mouths after heavy rain.

Why this level

  • Other jellyfish and stinging plankton Moderateraises risk
    above usual for the season · stronger wind than usual · waves toward the shore
  • Box jellyfish Lowusual background
    calm water and rain, usual for the season
  • Bluebottles (Portuguese man o’ war) Lowlowers risk
    below usual for the season

October is an average month for jellyfish on the eastern Gulf coast, the wind is light or along the shore, the sea is calm (waves ~0.1 m), so the risk level is moderate. 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.

Long Beach (Hat Sai Yao, Koh Chang): jellyfish month by month

  1. 0%JanJanuary: Usually moderate risk. High risk on 0% of days. Onshore wind on 39% of days. Official warnings: 0.
  2. 4%FebFebruary: Usually moderate risk. High risk on 4% of days. Onshore wind on 75% of days. Official warnings: 0.
  3. 8%MarMarch: Usually moderate risk. High risk on 8% of days. Onshore wind on 88% of days. Official warnings: 0.
  4. 0%AprApril: Usually low risk. High risk on 0% of days. Onshore wind on 88% of days. Official warnings: 0.
  5. 0%MayMay: Usually moderate risk. High risk on 0% of days. Onshore wind on 80% of days. Official warnings: 0.
  6. 27%JunJune: Usually moderate risk. High risk on 27% of days. Onshore wind on 100% of days. Official warnings: 0.
  7. 41%JulJuly: Usually moderate risk. High risk on 41% of days. Onshore wind on 98% of days. Official warnings: 0.
  8. 48%AugAugust: Usually moderate risk. High risk on 48% of days. Onshore wind on 99% of days. Official warnings: 0.
  9. 25%SepSeptember: Usually moderate risk. High risk on 25% of days. Onshore wind on 91% of days. Official warnings: 0.
  10. 23%OctOctober: Usually moderate risk. High risk on 23% of days. Onshore wind on 33% of days. Official warnings: 0.
  11. 0%NovNovember: Usually moderate risk. High risk on 0% of days. Onshore wind on 8% of days. Official warnings: 0.
  12. 0%DecDecember: Usually low risk. High risk on 0% of days. Onshore wind on 8% of days. Official warnings: 0.
  • typical level that month
  • bar and % — share of high-risk days
  • nofficial warnings, all years

Coordinates: 11.9578, 102.4301

Questions and answers

Can I swim at Long Beach (Hat Sai Yao, Koh Chang) today?

Today's estimated risk is moderate; main factor: stronger wind than usual. 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 Long Beach (Hat Sai Yao, Koh Chang) 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 Long Beach (Hat Sai Yao, Koh Chang)?

Based on 2022–2026 weather, the risk is most often elevated in July, August, September. Official warnings nearby: 0.

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.