Koh Samui
May 31, 2023

Koh Samui in May: What to expect

May on Samui gets an average of 215 hours of sun. That’s almost 7 hours a day – sound good? I think so.

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Koh Samui in May

A very hot mid-May afternoon at Kimpton Kitalay Samui

Whether you’ve planned it to perfection or you’re just lucky, May is a gorgeous time to visit Koh Samui – and there’s lots to look forward to besides sunshine. As for the climate, May is still Koh Samui’s ‘hot’ season. Given Samui’s location just a few degrees above the equator, that’s saying something. How to ensure you don’t melt? Read on for packing tips and hotel recommendations that will help you in the heat.

Is May a good time to visit Koh Samui?

Yes – if you’re prepared for strong heat. May on Samui gets an average of 215 hours of sun. That’s almost 7 hours a day – sound good? I think so. As well, May is pretty quiet compared to mid-to-late June and July/August when families arrive for holidays with school-aged children. However - let me repeat – it's very, very hot in May.

Koh Samui questions? Start here

The Koh Samui Guide: How do I? Where do I? What’s the best? Ready to get planning? The Koh Samui Guide gives you every scrap of my nearly 20 years’ Samui expertise: from how to choose your perfect beach, to where to enjoy romantic nights out, it’ll even help you hobble your way to hangover brunches (and will totally save a rainy day).

Where to stay in May

My pick: Bo Phut Resort and Spa

Bo Phut Resort and Spa

Want your own private pool villa? Come on in. Bo Phut Resort also offers ‘Spa Bath’ rooms with giant soaker tubs set into your outdoor terrace (however, in May, it might just be too hot to want a bath). Need to beat the heat? Try the resort's kayaks and windsurfs, or escape to the shade in the superb resort spa. Two on-site restaurants offer you a thousand guarantees that, yes, you will eat your body-weight in mango sticky rice and spring rolls.

See Rates + Details

Hotel Tip: Is Bophut good for families? Yes! Bophut’s quiet pace and range of restaurant options makes it ideal for families. A number of Bophut hotels offer kids clubs as well. Two things to note about Bophut Beach with kids? First, the sand is soft-packed and ‘sinky’, so you’ll get nowhere with a buggy/stroller. Similarly, it’s not the best beach for sand castles (try Choeng Mon).

More hotel ideas

Hotel questions? Start here

What to pack for May

1. Packable Daypack

Adventure easily. May is a great time of year to try a huge variety of adventures and excursions on Samui. (As long as you’re prepared for the heat). So, in addition to the things on my recommended Thailand packing list, it’s worthwhile to bring a day-trip bag that you can keep stocked with essentials (recap: sunscreen, sunscreen and more sunscreen).  This backpack folds down to the size of a water bottle so it’s easy to have on hand when you need it.

2. Electrolyte Drink Tablets

Avoid wilting: To keep your electrolyte supply up when you’re sweating so much, a few tubes of electrolyte tabs are good to bring. Keep a tube in your bag or pocket and they’re easy to add to a bottle of water when needed.

3. The Koh Samui Guide

Ready to start planning the Thailand trip of your dreams? Assuming you’re as click-happy as me, you might have as many as 2,984 browser tabs open. Better plan: start with The Koh Samui Guide. It’s packed with every scrap of expertise I’ve gathered in my twenty years of Samui exploration, and a nice place to sleep in Bophut is just the start. From adapters and airlines to yoga and zip-lining, it’s your total guide to Koh Samui‚ in one easy download.

4. Supergoop! Unseen Sunscreen

If you burn easily (or are travelling to Samui with children), also consider some UPF-protective clothing like swim shirts/rash-guards, etc.

What to wear on Koh Samui in May?

Linen! This is perhaps my best what to wear in Thailand tip: wear 100% linen, from top to bottom. Double-check the labels: many fabrics can be sneaky linen blends and a majority of cotton or rayon won't offer the same magically cooling properties.

Packing questions? Start here

Mosquito questions? Get answers to all your mosquito questions, discover my favourite repellent, and learn how to win the mosquito battle.

Weather in May

A scorching May afternoon in Nathon

May averages

  • Temperature: 30°C / 86°F
  • Sunshine (hours/day): 6
  • Rainy days: 9 days (160 mm / 6 inches)
  • Sea temperature: 28°C / 82°F

What’s the weather like on Koh Samui in May?

Expect temperatures anywhere between 28-35 degrees Celsius (that’s 82-95 Fahrenheit) – perhaps with the occasional shower.

How much does it rain on Koh Samui in May?

Minimal. Worst case – it rains a little bit across an average of 9 days in 31. Storms are usually pretty quick in May – rarely does the "rain/thunder" icon on your weather forecast mean that it rains all day, as in somewhere like the UK. Koh Samui weather does have seasonal variation, but May is (typically) still the hot, dry season.

A rainy May afternoon at Centara Reserve Samui

How hot is it on Koh Samui in May?

May’s usually a hot month on Samui’s calendar. And then there was May 2023.

It. Was. SO. Hot.

SO HOT.

How hot?

37.2°C on the thermometer, translated to feeling like 47-49°C with Samui’s extra credit humidity. That’s 98.96°F feeling like a sticky 120°F. Think Phoenix in August in a Florida swamp. HOT.

Plan to spend most of your time either next to a fan, in air conditioning or in a cool pool. This would be tricky weather in which to undertake many physical activities – May’s heat requires lazy days. Put all your pandemic training to good use and plan to lounge all day, moving only to eat and day-drink.

Is it rainy season in May?

No, any rain is just ‘regular’ – not scheduled. Don't panic about the possibility of rain. Samui's tropical storms are amazing – and they don't last long at this time of year.

May events calendar

May 2024 events

Your May FAQs

What are the best things to do on Koh Samui in May?

On Koh Samui, I like a mixture of about 20% scheduled activities to 80% "let's see what happens today". If it involves something alcoholic happening in a coconut, so much the better. As for things to do in May, can I interest you in some lazy days? It’s very hot – you really don’t want to exert yourself.

In no particular order, my favourite things to do include: eat and drink a lot, laze around, read all the books I wanted to read all year, spa days and massages, try out new cafes and coffee shops, fan-cooled board games and jigsaws (with an ocean view).

The Koh Samui Guide: The Koh Samui Guide is fully stocked with rainy day ideas, including a full checklist of activities to keep you perfectly entertained in any weather.

Koh Samui parties in May?

Nikki Beach Resort & Spa Koh Samui

Is May or June better on Koh Samui?

Refer to everyone’s favourite Thai-glish phrase: ‘Same same’. Your daylight hours will be 11 minutes longer in early June versus early May. As for the weather? Can you tell the difference between 1°C? On average, rainfall is very slightly heavier in May but over the same amount of time (so, if it rains, it’s just more emphatic in May than in June). Both are great times to visit Koh Samui.

Is Koh Samui busy in May?

Two pieces of certain science: (1) Children in the UK, Australia, the States and Canada (and much of the rest of the world) are in school in May. (2) You can always find peace and quiet somewhere on Koh Samui, no matter the month.

Is Koh Samui or Phuket better in May?

Note that Phuket gets twice as many rainy days as Samui in May – 18, on average.

  • Temperature (avg): 30°C on Koh Samui vs 29°C in Phuket
  • Sunshine (hours): 6 on Koh Samui vs 8 in Phuket
  • Rainy days (avg): 9 days (160 mm) on Koh Samui vs 18 days (200 mm) in Phuket
  • Sea temperature: 28°C on Koh Samui vs 30°C in Phuket

What are hotel rates like for Koh Samui in May? How do they compare between May and June?

May

June

Between the four hotels, rates between May and June are fairly similar. Rates via Booking.com for a random night in May 2024.

An early May sunset

When are sunrise and sunset on Koh Samui in May? What time does it get dark?

Sunrise on May 1st is a bright and early 6:03am, but dawn breaks around 5:15am – a favourite time of day for runners and yoga people hoping to exercise outside during May's incredible heat. Sunset is at 6:30pm on the dot.

Is May a good time for a wedding or honeymoon on Koh Samui?

Yes. Although you’ll need to make sure your guests are prepared for the considerable heat. Plan on an evening ceremony with a lot of fans, rather than a noon beach ceremony with no shade.

Koh Samui in May

Time travel: Koh Samui in May 2010

The Koh Samui Guide: What’s next? To make sure you enjoy it all in full, you’ll need The Koh Samui Guide. You might wind up more excited, but definitely better prepared. Enjoy!

“I recently bought your guide for Koh Samui and it has been my go-to tool in planning my trip there this summer. Thank you for creating it!” – Jill

Weather details via Weather Spark, which promises that “snow is exceptionally unlikely to fall at this location in May”.