The Koh Samui weather in November is the most misunderstood month in Gulf of Thailand travel planning — it is the tail end of the northeast monsoon, which means the first half of November can be genuinely challenging while the second half shows significant and rapid improvement. Understanding the Koh Samui November weather pattern in detail — not just “avoid the rainy season” — gives you a significant planning advantage, particularly if November is the only time you can travel. This complete guide to Koh Samui weather November covers the month week by week, the transition out of monsoon, what to expect and how to book smart.
According to Thailand's Meteorological Department, November marks the official end of the northeast monsoon on Koh Samui — rainfall typically peaks in October and begins its significant decline through November, with late November often delivering conditions that approach the early dry season in quality.
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Koh Samui Weather November — Quick Summary
| Category | Early Nov (1–10) | Mid Nov (11–20) | Late Nov (21–30) |
|---|---|---|---|
| ☀️ Sunshine | 3–5h/day | 4–6h/day | 6–8h/day |
| 🌧️ Rain probability | 60–75% | 40–55% | 25–35% |
| 🌊 Sea conditions | Rough | Moderate–Rough | Moderate–Calm |
| ⛵ Boat trips | ❌ Most cancelled | ⚠️ Some run | ✅ Most run |
| 🏖️ Beach | ⚠️ Challenging | ⚠️ Variable | ✅ Generally good |
| 🏨 Hotel prices | -35–45% | -25–35% | -15–20% |
November on Koh Samui is not one month — it is two very different halves. Early November (1–15) is effectively still monsoon season — challenging weather, rough seas, many boats cancelled. Late November (15–30) sees a dramatic improvement as the monsoon retreats — by the last week of November, conditions are often approaching the early dry season. If you must visit in November, target the last 10 days of the month.
Koh Samui Weather November — Week by Week
Week 1 (1–7 November) — Monsoon Tail
The first week of November sees Koh Samui November weather at its most challenging — the northeast monsoon is still active, rain probability remains at 65–75% and sea conditions are rough. Ang Thong Marine Park tours and most boat trips are cancelled. This is the worst week to visit Koh Samui in November. If booked, focus on spa, cooking classes, temple visits and resort activities.
Week 2 (8–14 November) — Transition Begins
The second week shows the first signs of the November Koh Samui weather transition — rain probability drops to 50–60%, with occasional clearer mornings appearing. Some boat operators begin running again on good days. Sea conditions remain moderate to rough. The improvement is noticeable but conditions are still unreliable. Book all activities with free cancellation.
Week 3 (15–21 November) — Significant Improvement
Mid-November marks a turning point in the Koh Samui weather in November — sunshine hours increase to 5–7 per day, rain probability drops to 35–45% and the sea begins to calm. Most ferry services are running normally. Some Ang Thong tours and snorkeling trips resume. Hotel prices begin their seasonal increase as conditions improve. This week represents reasonable value — improving weather at still-reduced prices.
Week 4 (22–30 November) — Near Dry Season
The final week of November often surprises visitors with genuinely good conditions — sunshine 6–8 hours daily, rain probability below 30% and calm enough seas for most boat trips. The Koh Samui November weather in the last 10 days of the month can be indistinguishable from early December — the beginning of the official dry season. Hotel prices are still 10–15% below December peak, making this window excellent value.
Koh Samui Weather November — Temperature Data
| Period | Max Temp | Min Temp | Sea Temp | Humidity | UV Index |
|---|---|---|---|---|---|
| Early November | 28–29°C | 23°C | 27°C | 85–90% | High |
| Mid November | 28–30°C | 23°C | 27°C | 80–85% | High |
| Late November | 29–30°C | 22°C | 27°C | 75–80% | Very High |
Koh Samui Weather November — Activities Guide
| Activity | Early Nov | Mid Nov | Late Nov |
|---|---|---|---|
| Ang Thong Marine Park | ❌ Cancelled | ⚠️ Check day before | ✅ Most run |
| Five Islands Snorkeling | ❌ Cancelled | ⚠️ Variable | ✅ Good |
| Koh Phangan ferry | ⚠️ Delays possible | ✅ Usually runs | ✅ Normal |
| Beach swimming | ⚠️ Rough | ⚠️ Variable | ✅ Generally safe |
| Scooter ring road | ⚠️ Wet roads | ⚠️ Morning OK | ✅ Good |
| Big Buddha · Temples | ✅ Always fine | ✅ Always fine | ✅ Always fine |
| Spa · Massage | ✅ Perfect | ✅ Perfect | ✅ Perfect |
| Fisherman's Village | ✅ Open | ✅ Open | ✅ Open |
| Night markets | ⚠️ Some close | ✅ Mostly open | ✅ Open |
The optimal Koh Samui November weather strategy is clear: if possible, target arrival around 20–22 November and depart in early December. This captures the rapid weather improvement in the final 10 days of November — conditions that approach the dry season at prices still 10–15% below December peak. Book free cancellation accommodation throughout.
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Koh Samui Weather November vs Other Months
| Month | Weather | Rain | Sea | Price | Verdict |
|---|---|---|---|---|---|
| January | ☀️ Perfect | Very low | Calm | +50% | Best · Expensive |
| March | ☀️ Perfect | Low | Calm | +15% | Best value dry |
| July | 🌦️ Mixed | Medium | Moderate | -15% | Acceptable |
| October | ⛈️ Monsoon | Highest | Rough | -40% | Worst · Avoid |
| November (early) | 🌧️ Wet | High | Rough | -35% | Challenging |
| November (late) | 🌤️ Improving | Medium-low | Calming | -15% | Good value |
| December | ☀️ Good | Low | Calm | +30% | Dry season begins |
Koh Samui Weather November — November vs Phuket
An important consideration for Koh Samui weather in November is the comparison with Thailand's Andaman coast:
| Factor | Koh Samui November | Phuket November |
|---|---|---|
| Monsoon phase | NE monsoon ending | NE monsoon — but lighter on Andaman |
| Early November | ⭐ Still wet | ⭐⭐⭐⭐ Already improving |
| Late November | ⭐⭐⭐⭐ Good improvement | ⭐⭐⭐⭐⭐ Excellent |
| Sea conditions | Rough early · Calming late | Calming throughout November |
| Verdict | Late Nov good · Early Nov difficult | Better than Koh Samui all November |
Unlike July (where Koh Samui clearly beats Phuket), November is the one month where Phuket has the weather advantage. The Andaman coast's southwest monsoon has ended by November while Koh Samui is still in the tail of its northeast monsoon. If you have flexibility in November and prioritise weather — Phuket in November is generally better than Koh Samui in November, particularly in the first two weeks.
Koh Samui Weather November — What to Do
A November visit to Koh Samui — particularly early November — calls for a different approach than a peak-season visit. These activities work well regardless of the November Koh Samui weather:
| Activity | Rain-Proof | Cost | Why Good in November |
|---|---|---|---|
| Spa retreat (multi-day) | ✅ Fully indoor | 2,000–15,000 THB/day | Best time for lengthy spa programme |
| Thai cooking course | ✅ Fully indoor | 1,200–2,000 THB | Fewer tourists · More personal attention |
| Na Muang Waterfall | ✅ Better in Nov rain | Free | Full flow · Dramatic · Fewer visitors |
| Wat Khunaram (mummy monk) | ✅ Covered temple | Free | No queues · Cool inside |
| Fisherman's Village exploration | ✅ Covered areas | Free | Authentic atmosphere · Locals present |
| Local food markets | ⚠️ Partially covered | 100–300 THB | Cheaper in low season · Less crowded |
| Muay Thai evening | ✅ Covered arena | 400–800 THB | Local atmosphere · Good in any weather |
Koh Samui Weather November — Booking Tips
- Free cancellation is essential — a storm event in early November can make parts of your trip unworkable. Book via Agoda with free cancellation on all accommodation throughout your November visit.
- Target late November arrival — the final 10 days of November deliver significantly better conditions at prices 10–15% below December. Arriving 20–22 November and departing in early December is the optimal November strategy.
- Book activities with 24h free cancellation — GetYourGuide offers free cancellation on most Koh Samui tours. Book Ang Thong and Five Islands snorkeling but cancel and rebook if conditions are poor the day before.
- Consider spa-heavy itinerary — November is actually an excellent time for a wellness holiday on Koh Samui. The island's luxury spa infrastructure (Anantara, Ritz-Carlton Spa Village, Four Seasons) is at its quietest and most accessible. A spa-focused November visit avoids weather frustration entirely.
- Hotel prices — negotiate or use Agoda deals — November is low season and hotels are motivated to fill rooms. Agoda often lists last-minute November deals that deliver five-star properties at three-star prices.
🏨 Find November Hotel Deals — Agoda →
FAQ — Koh Samui Weather November
Is November a good time to visit Koh Samui?
The answer depends entirely on which part of November. Early November (1–15) is the tail of the monsoon — challenging weather with rain likely most days and rough seas. Late November (20–30) is excellent — the monsoon has retreated, sunshine increases dramatically and conditions approach the dry season at prices still 10–15% below December peak. For Koh Samui weather in November, target the final 10 days of the month for best results.
How much does it rain in Koh Samui in November?
November is still a wet month overall — averaging 250–350mm of rainfall, though this drops significantly through the month. Early November sees rain on 15–20 days; late November typically has rain on only 5–10 days. The Koh Samui November weather transition is one of the most dramatic month-to-month improvements in the island's annual cycle — the difference between 1 November and 30 November can be extraordinary.
What is the temperature in Koh Samui in November?
Koh Samui weather November temperatures range from 28–30°C maximum during the day and 22–23°C at night — among the most comfortable temperatures of the year. The high humidity (80–90% early November, improving to 75–80% late November) makes the temperature feel warmer than the numbers suggest, but November is not as intensely hot as April.
Can you swim at Koh Samui in November?
Swimming conditions in November improve through the month — early November sees rough seas on the east coast (Chaweng, Lamai) making swimming potentially dangerous, while the calmer north coast beaches (Maenam, Bophut, Choeng Mon) remain swimmable throughout. By late November, all beaches are generally safe for swimming and the sea temperature of 27°C is comfortable. Koh Samui weather November sea conditions improve rapidly after mid-month.
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