Monday, October 19, 2026 · Thailand
Skin weather in Koh Samui UV index & humidity today
What today’s weather in Koh Samui does to your skin – based on current forecast data for UV, humidity and air quality.
Updated Oct 19, 2026, 3:10 PM local time
Today · Temperature26 to 28 °C
Low and high-
UV index
5.3
moderate
Peak UV index today: 5.3 – moderate.
From UV 3, the WHO recommends sun protection: sunscreen with SPF and shade around midday.
-
Humidity
89%outdoors
humid
Average humidity today: 89%.
Humid air – lighter textures often feel more comfortable today.
-
Pollen
–
No pollen forecast is available for this region.
-
Air quality
35EAQI
fair
European Air Quality Index up to 35 – fair. Fine dust (PM2.5) averages 2.1 µg/m³.
Clean air – no extra cleansing needed.
Tomorrow
- 26 to 31 °C
- UV 2 · low
- 82% · humid
- Air quality: moderate
Skin climate in Koh Samui through the year
When the air in Koh Samui is driest and when the sun is strongest – based on climate data from recent years.
- In Koh Samui the average daily temperature stays above 15 °C all year – heating is rarely needed. Outdoor humidity ranges between 77% and 82%.
- All year round the midday sun in Koh Samui climbs higher than 45° – your shadow is shorter than you are. According to the WHO shadow rule, UV is then usually high.
- March brings the most sunshine, with around 329 hours.
| Month | Sunshine | Midday sun | Humidity outdoors | Indoors when heated | Avg. high |
|---|---|---|---|---|---|
| Jan | 319 h | 59° | 77% | – | 27.5 °C |
| Feb | 304 h | 67° | 79% | – | 28.2 °C |
| Mar | 329 h | 78° | 79% | – | 29.2 °C |
| Apr | 320 h | 90° | 79% | – | 30.1 °C |
| May | 316 h | 81° | 80% | – | 30.2 °C |
| Jun | 291 h | 76° | 77% | – | 30.2 °C |
| Jul | 288 h | 78° | 79% | – | 29.9 °C |
| Aug | 292 h | 86° | 79% | – | 29.9 °C |
| Sep | 267 h | 83° | 80% | – | 29.2 °C |
| Oct | 265 h | 71° | 82% | – | 28.3 °C |
| Nov | 255 h | 61° | 82% | – | 27.9 °C |
| Dec | 295 h | 57° | 78% | – | 27.6 °C |
Indoors when heated = humidity when outdoor air is warmed to 21 °C (only months with a daily average below 15 °C). Midday sun = sun angle in mid-month.
Frequently asked questions
What is the UV index in Koh Samui today?
Today (October 19) the UV index in Koh Samui reaches up to 5.3 – moderate. From UV 3, the WHO recommends sun protection: sunscreen with SPF and shade around midday.
How dry is the air in Koh Samui today?
Average humidity today: 89%. Humid air – lighter textures often feel more comfortable today.
When is the air driest in Koh Samui?
In Koh Samui the average daily temperature stays above 15 °C all year – heating is rarely needed. Outdoor humidity ranges between 77% and 82%.
When is UV strongest in Koh Samui?
All year round the midday sun in Koh Samui climbs higher than 45° – your shadow is shorter than you are. According to the WHO shadow rule, UV is then usually high. March brings the most sunshine, with around 329 hours.
Your skin weather, every morning.
Lumée reads UV, humidity, pollen and air quality for your location and turns them into skincare that fits this exact day.
Skin weather nearby
All cities →Data: WDTEC GmbH’s own weather servers – temperature, UV index and humidity from weather models, air quality and pollen from the Copernicus Atmosphere Monitoring Service (CAMS). Ratings: UV per WHO, air quality per European Air Quality Index, pollen per NAB. Skincare tips are general recommendations and do not replace medical advice.