Koh Samui Rainy Season: When Is It and What to Expect?

When is rainy season on Koh Samui? It’s my most-asked question with a “kind of, sort of” answer. Is it crazy to come to Samui during rainy season? Well, that too depends on what you have in mind for your time in Thailand.

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When is Koh Samui’s rainy season?

First things first: note that the timing of Koh Samui’s rainy season is different from other parts of Thailand, including Phuket. As much as anyone can predict the weather these days, typically Koh Samui’s rainy season happens in:

late October
through November
to early or mid-December
sometimes into early January

January 2017, January 2020 and November 2021 also saw very unusual, near-Biblical amounts of rain which caused island-wide flooding for a few days. All three events were absolutely freak weather but always a good reminder to have travel insurance.

Are you determined to miss rainy season?

Find out when is the best time to visit Koh Samui and learn which is Koh Samui’s sunniest month. Do note, though – total truthiness here – it can rain at any time of year in the tropics (and it often does).

Does it rain at other times of the year?

Oh yes, it does! Rainy season or not, it will probably rain at some point during your trip. Tropical downpours come with the territory and make Koh Samui so incredibly lush. Outside of rainy season, a rainstorm is usually a fleeting affair – perfect for cutting the humidity. If you’ve never been to the tropics, it’s a fantastic show.

What is rainy season like on Koh Samui?

The world will end before your very eyes. Just kidding. It totally depends on the year. Some years it’s “bad” and power cuts are frequent, other years are just a tad soggy. Speaking generally, you might expect:

Choppy and atmospheric seas
Stronger breezes than usual
Quiet beaches & restaurants
Local roads can – and do – flood
Maybe no swimming

During rainy season, the sea around Koh Samui isn’t suitable for swimming, water-sports or boating excursions. Angthong Marine Park is usually closed in rainy season, though sometimes it stays open if the weather isn’t bad.

Expect bumpy boat rides

Ferries to nearby islands Koh Tao and Koh Phangan, as well as from the mainland at Surat Thani, can involve rough crossings. Bring the Dramamine.

Car rental is a good idea

As for island exploration – you’ll almost certainly want to rent a car and stick to the island’s main, paved roads. Koh Samui is a very hilly island and flash floods can happen as heavy rainfall comes down from the mountains.

Improve your trip by … a thousand-million percent?

Make a Koh Samui rainy season (or rainy day) your very best holiday ever. Use The Koh Samui Guide to plan all your eating, drinking and island activities – no wellies required.

Should people visit Koh Samui during rainy season?

Yes! Should you? Let’s find out.

NO – don’t come in rainy season: If you’re coming to Koh Samui for the picture-postcard perfect beach, I wouldn’t recommend betting your sun holiday during this period. Hopes hung on nothing but sunshine could be disappointed. Try coming in March instead – it’s typically Koh Samui’s sunniest month.

YES – give it a go: I love a good tropical downpour, especially with a view out to sea. So a rainy season visit isn’t necessarily crazy – you just need to know what’s in store. While sunshine might be fleeting, Koh Samui’s rainy season holds huge appeal for relaxation and lazy days – a time filled with:

yoga
a big stack of books
Thai cooking classes
spa days (often with good promos)

As with anything – it’s who you’re with, not what you’re doing.

Shhh … The best rainy season secret

One more reason? You’ll find great hotel rates, and then often get the entire place to yourself. Enjoy the entire island without every needing a spa appointment or restaurant reservation.

What to wear during rainy season?

You’ll want to make sure your packing is prepared a little differently at this time of year – especially in your shoe selection. Find out what to wear in Thailand’s rainy season:

What is there to do on a rainy day in Koh Samui?

There’s plenty to do on Koh Samui whatever the weather. As and when (not I didn’t say “if” – this is the tropics) it rains, the tropical gardens love it and you can easily turn to a very long list of equally enjoyable rainy day activities.

There’s a big difference between Samui rain and rain in the real world. When it rains here, you take your book and move to your hotel’s sala. Or your covered balcony. Or your outdoor living room. Or simply switch from your beach chair to the beach restaurant, which will drop down clear plastic rain-screens when it rains. Or maybe you give up on the beach and go to the spa. Whatever the decision, rain is a good thing.