Ko Samui weather in May (Thailand)

This month is known as a warm month. The average maximum daytime temperature in Ko Samui in May lies at 30.2°C (86.36°F). The average minimum temperature goes down to around 27.0°C (80.6°F) (often the minimum temperature is noted at night).

May is part of the rainy season with an average precipitation of 184mm (7.3 inches). There are generally around 16 rainy days. The sun also shows itself regularly this month with 193 hours of sunshine during the entire month.


Ko Samui, monthly averages in May

Show in Fahrenheit
Min Temperature 27 °C  
Max Temperature 30 °C  
Water Temperature 29 °C *  
Chance of Rain 56%  
Precipitation 184mm  
Rainy days 17 days  
Humidity 80% *  
Sunshine 193 hrs *  

Where to stay in Ko Samui

Where to go in Thailand in May

Find out more about the weather in Thailand in May and which places have the best weather conditions in this month.

Legend perfect weather pleasant tolerable unpleasant poor
Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20-29ºC / 68-84ºF and not too much precipitation (less than 90mm / 3.5inches a month).

So what to wear in May? Visitors traveling to Ko Samui should plan on bringing a totally waterproof coat since it will often be raining. However, also bring your summer cloths because it can be very warm or even hot. With a water temperature of around 29.3°C (84.74°F), this is a great month to swim so bring your swimwear.

What To Do

We rated the following activities from 1 (least suitable) to 10 (best) to do in May.

Outdoor sports

Interested in more climate information?

Weather and Climate provides you with all the information you need about the climate in Ko Samui.

Our site offers climate and forecast data for almost all countries in the world. Are you going to Thailand? On this website you can find historical weather averages for many cities in Thailand. Not sure yet where to go? We now have a tool which suggests which destination suits your ideal climate conditions. Find out where to go with our weather planner.