Jellyfish at Maenam Beach

หาดแม่น้ำ · Koh Samui · Gulf of Thailand

Risk today · 24 Oct 2026Moderate

Main factor: Calm water and rain

Conditions or reports nearby make an encounter more likely.

Today the jellyfish risk at Maenam Beach is moderate. 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. TodayModerate3 m/s NW — Wind: up to 3 m/s, blowing from NW. 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.2 mm — Rain: 2 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  2. TomorrowModerate2 m/s E — Wind: up to 2 m/s, blowing from E. 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.13 mm — Rain: 13 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  3. Mon 26Moderate5 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.0.3 m — Waves: up to 0.3 m during the day. Strong onshore waves wash jellyfish ashore; box jellyfish prefer calm water.10 mm — Rain: 10 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  4. Tue 27Moderate4 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.37 mm — Rain: 37 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  5. Wed 28Low3 m/s E — Wind: up to 3 m/s, blowing from E. 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.4 mm — Rain: 4 mm in the day. Box jellyfish are more common near river mouths after heavy rain.
  6. Thu 29Low3 m/s E — Wind: up to 3 m/s, blowing from E. 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.20 mm — Rain: 20 mm in the day. Box jellyfish are more common near river mouths after heavy rain.

Why this level

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

October is an average month for jellyfish on the Samui archipelago, the wind blows from the sea (~0.7 m/s), 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.

Maenam: jellyfish month by month

  1. 0%Jan1January: Usually low risk. High risk on 0% of days. Onshore wind on 77% of days. Official warnings: 0. Eyewitness reports: 1.
  2. 23%Feb6February: Usually moderate risk. High risk on 23% of days. Onshore wind on 38% of days. Official warnings: 0. Eyewitness reports: 6.
  3. 29%Mar17March: Usually moderate risk. High risk on 29% of days. Onshore wind on 20% of days. Official warnings: 1. Eyewitness reports: 7.
  4. 13%Apr6April: Usually moderate risk. High risk on 13% of days. Onshore wind on 19% of days. Official warnings: 0. Eyewitness reports: 6.
  5. 1%May2May: Usually moderate risk. High risk on 1% of days. Onshore wind on 13% of days. Official warnings: 0. Eyewitness reports: 2.
  6. 0%Jun3June: Usually moderate risk. High risk on 0% of days. Onshore wind on 1% of days. Official warnings: 0. Eyewitness reports: 3.
  7. 0%Jul24July: Usually moderate risk. High risk on 0% of days. Onshore wind on 0% of days. Official warnings: 2. Eyewitness reports: 4.
  8. 32%Aug16August: Usually moderate risk. High risk on 32% of days. Onshore wind on 1% of days. Official warnings: 0. Eyewitness reports: 16.
  9. 1%Sep4September: Usually moderate risk. High risk on 1% of days. Onshore wind on 7% of days. Official warnings: 0. Eyewitness reports: 4.
  10. 0%Oct7October: Usually moderate risk. High risk on 0% of days. Onshore wind on 62% of days. Official warnings: 0. Eyewitness reports: 7.
  11. 1%Nov2November: Usually moderate risk. High risk on 1% of days. Onshore wind on 83% of days. Official warnings: 0. Eyewitness reports: 2.
  12. 0%Dec1December: Usually low risk. High risk on 0% of days. Onshore wind on 100% of days. Official warnings: 0. Eyewitness reports: 1.
  • typical level that month
  • bar and % — share of high-risk days
  • nofficial warnings, all years
  • neyewitness reports, all years

Coordinates: 9.5719, 99.9986

Questions and answers

Can I swim at Maenam Beach today?

Today's estimated risk is moderate; 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 Maenam 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 Maenam Beach?

Based on 2022–2026 weather, the risk is most often elevated in February, March, August. Official warnings nearby: 3.

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.