When Is the Best Time to Visit Koh Samui?
The best time to visit Koh Samui is January to March for dry weather, blue skies, and calm seas. For fewer crowds and better hotel deals, May to July is a great alternative. October and November are the rainiest months and best avoided for a classic beach holiday.
Here’s the quick summary:
– Best weather: January to March
– Best value: Mid-March to July
– Avoid if possible: October and November
– Still good but unpredictable: August and September
– Christmas holidays: Late December is a great time to come, but plan ahead
So what does that actually mean for your trip?
We’re a family of four who’ve been living in Thailand since 2019. We recently moved back to Koh Samui after spending a couple of years on the neighboring island Koh Phangan. And let me tell you, we’ve seen every single month on Samui. Sunshine, floods, heatwaves, downpours… we’ve been through it all.
Our Quick Picks
🏡 Check for special deals at Hyatt Regency Samui here.
🏝️ Read about the best family areas and things to do in Samui with kids.
What’s the Best Month to Visit Koh Samui?
The best time to visit Koh Samui is January to March if you want dry weather, blue skies, and calm seas. February stands out as the driest month of the year, nearly zero rainfall, around 9 hours of sunshine a day, and seas calm enough for snorkeling almost anywhere on the island.
If you’re looking for fewer crowds and better hotel deals, May to July is a strong shoulder season alternative. You’ll still get plenty of sunny days, but prices drop noticeably and the beaches feel like they belong to you again.
The rainiest months are October and November. Try to avoid these if a beach holiday is the goal.
What Is the Worst Time to Visit Koh Samui?
Honestly, the worst time to visit Koh Samui is October and November. This is peak monsoon season. Rain can last for hours or even days. Seas are rough, ferry crossings get canceled, and some tours stop operating altogether.
That doesn’t mean the island shuts down. If you’re looking for peace, low prices, and don’t mind rain, these months can still have their charm.
Verdict: Worst for beach weather and island hopping. Best for slow travel, quiet cafés, and deep hotel discounts.
What’s the Weather Like in Koh Samui Month by Month
| Month | Weather | Avg Temp (°C) | Rainfall | Sunshine (hrs/day) | Mid-Range Hotel (USD) |
|---|---|---|---|---|---|
| January | Dry, breezy | 26-30 | Low ~60mm | 8 | $163 |
| February | Peak sun, peak crowds | 26-31 | Very low | 9 | $163 |
| March | Sunny, getting hotter | 27-32 | Low | 9 | $130 |
| April | Hottest month | 27-33 | Low, humidity up | 8 | $120 |
| May | Hot, occasional showers | 28-33 | Moderate | 7 | $110 |
| June | Calm, mostly sunny | 28-32 | Moderate | 7 | $100 |
| July | Warm, humid | 28-32 | Moderate | 6 | $110 |
| August | Rain increasing | 28-32 | Increasing | 7 | $120 |
| September | Warm and wet | 27-32 | High | 6 | $100 |
| October | Monsoon begins | 27-31 | Heavy | 5 | $90 |
| November | Peak rainy season | 26-30 | Very heavy | 4 | $95 |
| December | Rainy start, sunny finish | 26-30 | Moderate to low | 6 | $150 |
January in Koh Samui
January is one of the most popular months to visit. The skies are usually clear, the humidity is lower, and the sea is calm.
- Weather: Dry, breezy, and beautiful
- Average temp: 79-86°F (26-30°C)
- Rainfall: Low, around 60 mm
- Sunshine: About 8 hours a day
- Mid-range hotel price: $163 (€150)
It’s high season, so the island gets busy. If you’re coming in January, book early.
⚠️ Note: In 2025, the rainy season decided to hang around until mid-January. So even during “dry season,” the weather can be unpredictable. In 2026, it feels much drier so far.
February in Koh Samui
February is one of the driest and sunniest months. Great for swimming, snorkeling, or just doing nothing on the beach.
- Weather: Peak weather, peak crowds
- Average temp: 79-88°F (26-31°C)
- Rainfall: Very low
- Sunshine: About 9 hours a day
- Mid-range hotel price: $163 (€150)
Expect crowds and higher prices. It’s still totally worth it if you want nearly perfect weather.
March in Koh Samui
March is hotter but still mostly dry. The beaches are less crowded than earlier in the year, and hotel prices start to dip a little too.
- Weather: Still sunny, getting hotter
- Average temp: 81-90°F (27-32°C)
- Rainfall: Low
- Sunshine: Around 9 hours a day
- Mid-range hotel price: $130 (€119)
If you want sun without peak season chaos, March is a great time to come. Prices are lower than January and February, and you still get almost identical weather.
April in Koh Samui
April is hot and humid, but fun. Songkran (Thai New Year) brings a full-on water fight to the streets.
- Weather: The hottest month of the year
- Average temp: 81-91°F (27-33°C)
- Rainfall: Still low, but humidity is up
- Sunshine: Around 8 hours a day
- Mid-range hotel price: $120 (€110)
Great if you love sunshine and don’t mind the heat. Also cheaper than earlier months. Midday can be intense, so plan beach time for early mornings and late afternoons.
May in Koh Samui
May is still hot, but you’ll start to see more clouds and occasional tropical showers. This is where shoulder season begins, and it’s worth embracing.
- Weather: Hot with a chance of rain
- Average temp: 82-91°F (28-33°C)
- Rainfall: Moderate
- Sunshine: Around 7 hours a day
- Mid-range hotel price: $110 (€100)
Tourist numbers go down, and so do hotel rates. Most days still deliver beach time. It’s a nice balance if you’re flexible and want more island to yourself.
June in Koh Samui
June is a great mix of good weather and fewer people. Some clouds and showers, but still plenty of beach time, and the island has a lovely, unhurried feel.
- Weather: Calm and mostly sunny
- Average temp: 82-90°F (28-32°C)
- Rainfall: Moderate
- Sunshine: Around 7 hours a day
- Mid-range hotel price: $100 (€91)
If you’re looking for a peaceful trip without crowds, June delivers. I’m actually writing this article in early June, from a sunny café on Koh Samui. The sky’s clear and I’m about to head to the beach with my daughters. That’s what I love about this time of year.
July in Koh Samui
July brings slightly more rain but nothing too dramatic. Most days are sunny or partly cloudy with short showers that clear up fast.
- Weather: Warm and humid
- Average temp: 82-90°F (28-32°C)
- Rainfall: Moderate
- Sunshine: Around 6 hours a day
- Mid-range hotel price: $110 (€100)
Still a good time to visit, especially for families on school holidays. July is the most reliable of the shoulder season months for sunshine.
August in Koh Samui
August feels a bit unstable. Some years it’s lovely, others are wetter. It’s still very warm and lush, the island looks beautiful when it’s green.
- Weather: Rain is coming, but slowly
- Average temp: 82-90°F (28-32°C)
- Rainfall: Increasing
- Sunshine: Around 7 hours a day
- Mid-range hotel price: $120 (€110)
Good for flexible travelers who don’t mind a little rain. Families on school holidays make up most of the crowd in August. Just have a backup plan for rainy afternoons.
September in Koh Samui
September is the start of wetter times. Still warm, but the rain gets more regular and the skies stay grey for longer stretches.
- Weather: Warm and wet
- Average temp: 81-90°F (27-32°C)
- Rainfall: High
- Sunshine: Around 6 hours a day
- Mid-range hotel price: $100 (€91)
Not ideal for beach lovers but great if you’re on a budget or need quiet. The island empties out and prices drop.
October in Koh Samui
October marks the start of the full rainy season (also called monsoon season). You might get lucky with a few dry days early in the month, but don’t plan around it.
- Weather: Rainy season begins
- Average temp: 81-88°F (27-31°C)
- Rainfall: Heavy
- Sunshine: Around 5 hours a day
- Mid-range hotel price: $90 (€82)
Best for those who don’t mind staying indoors or finding cozy cafés. Ferry cancellations become more common. Beach clubs and tour operators start scaling back.
November in Koh Samui
November is usually the wettest month. It’s not the best time for beach holidays, but it can be peaceful if you’re into slow travel.
- Weather: Peak rainy season
- Average temp: 79-86°F (26-30°C)
- Rainfall: Very heavy
- Sunshine: Around 4 hours a day
- Mid-range hotel price: $95 (€86)
Expect travel delays and boat cancellations, but great deals on places to stay. Cafés are calm, roads are empty, and the island has a quietness that’s genuinely lovely, if rain doesn’t bother you.
December in Koh Samui
Early December can still be rainy, but by mid-month the dry season starts to return. Just in time for the holidays.
- Weather: Rainy start, sunny finish
- Average temp: 79-86°F (26-30°C)
- Rainfall: Moderate to low
- Sunshine: Around 6 hours a day
- Mid-range hotel price: $150 (€137)
By Christmas, the beaches are back in business. Book early, it gets busy fast.
Where to Stay in Koh Samui
If you’re planning your trip to Samui and wondering where to stay, here are our two absolute favorite Hotels in Koh Samui:
Anantara Bophut Resort
- From $250 (€232) per night (Premier Room)
- Lush gardens, calm beach, close to the Fisherman’s Night Market, read my review here!
Hyatt Regency Koh Samui
- From $230 (€212) per night (Family Room)
- Read my honest review here!
👉 You might also like my other Koh Samui articles:
– Best Family Resorts in Koh Samui
– Red Baron Sunset Cruise in Samui – Family Review
– Is Samui Elephant Sanctuary Ethical?
Is April a Good Time to Visit Koh Samui?
Yes, if you can handle the heat. April is one of the hottest months on Koh Samui. Rainfall is still low, but humidity is high, and midday heat can be intense. Early mornings and late afternoons are the most comfortable times to be outside.
April is also when Songkran (Thai New Year) takes place. The island turns into a giant water fight. Loud, fun, chaotic, and unforgettable. We celebrated Songkran here with our kids and loved it.
Is November a Good Time to Visit Koh Samui?
Usually no. November is typically the wettest month on Koh Samui. This is when the rainy season peaks. You can expect heavy downpours, grey skies, and rough seas. Boat trips are often canceled, and beach days are unreliable.
That said, November is quiet. Cafés are calm, roads are empty, and hotel prices drop significantly. If you don’t mind rain and enjoy slow travel, it can still work. Just don’t come for a classic beach holiday.
Is August a Good Time to Visit Koh Samui?
August is a hit-or-miss month. Some years are sunny with only short tropical showers. Other years feel noticeably wetter. It’s always warm, the island is lush and green, and prices are lower than in high season.
August is popular with families due to school holidays. You’ll still get beach days, but you need flexibility and a backup plan for rainy afternoons.
Is Koh Samui Better in July or August?
July edges it for most travelers. You get more reliable sunshine, moderate rainfall, and the island still feels alive without being packed.
August can be just as good, but it’s less predictable. Some years August is lovely. Others it feels like the rain is testing your patience. Both months are warm, green, and cheaper than peak season.
If you have a choice, go in July. If you’re on school holidays and August is your only option, go anyway, just bring a backup plan for rainy afternoons.
Is October a Good Time to Visit Koh Samui?
Honestly, October is risky. It marks the start of full monsoon season on Samui, and the rain can be relentless. Ferry cancellations are common. Some beach clubs and tour operators scale back operations.
That said, October isn’t November. You can still get patches of dry weather, especially early in the month. If you’re budget-conscious and flexible, early October can work. But if you’re planning a beach holiday, I’d push it to December when things dry out again.
Is Koh Samui Better Than Phuket?
For weather, they follow completely different seasonal patterns. Phuket gets its monsoon from May to October (the Andaman side). Koh Samui’s rainy season runs October to December (the Gulf of Thailand side).
That’s actually really useful. When Phuket is getting hammered by rain in June or July, Samui is often sunny. And when Samui is soggy in November, Phuket is usually lovely. So if you’re flexible on location and the timing of your trip falls in a rainy window for one island, the other is often a better bet.
For family travel, I personally prefer Samui. It’s smaller, easier to get around, and the vibe is more relaxed. But that’s a separate debate.
Key Takeaways
- Best weather: January to March.
- Best value: May to July, fewer crowds, still plenty of sunshine.
- Avoid: October and November (peak monsoon).
- Samui’s rainy season differs completely from Phuket’s.
- February has the least rain of any month.
- April is the hottest month, still low rainfall.
- Mid-December onward: dry season returns.
- Shoulder season (May, July) still offers real beach days.
Final Thoughts on the Best Time to Visit Koh Samui
I’m writing this article in early June, from a sunny café on Koh Samui. The sky’s clear, and I’m about to head to the beach with my daughters. That’s what I love about this time of year. It’s not as crowded, prices are lower, and you still get plenty of beautiful days like this.
But Koh Samui’s weather isn’t always predictable. We’ve had dry spells in November and surprise rain in January. If you can stay flexible and go with the flow, you’ll find your own perfect time to visit.
What’s your favorite time of the year to visit Koh Samui? Please let me know in the comments.
Thank you for reading and for making me part of your day!
Yours, Lulu
Frequently Asked Questions
What are the best months to go to Koh Samui?
January, February, and March are the best months. You get dry weather, low rainfall, calm seas, and around 8-9 hours of sunshine a day. March is slightly less crowded than January and February, which makes it a sweet spot for beach holidays if you want great weather without the full high-season rush.
What is the rainy season in Koh Samui?
Koh Samui’s rainy season runs from October to December, peaking in November. Unlike Phuket, Samui sits on the Gulf of Thailand side, so its monsoon timing is completely different. October brings heavy rain and rough seas. By mid-December, things start to dry out and the beach holiday season returns.
Is Koh Samui a year-round destination?
Yes, but with caveats. The island is open year-round and most months offer at least some good weather. October and November are the exception, heavy monsoon rain makes beach holidays unreliable during this window. Every other month has something going for it, even if it isn’t perfect.
