UV Index in Ko Samui, Thailand

Last updated: June 2, 2025

In Ko Samui, Thailand, being aware of the UV Index is crucial for protecting your skin from harmful ultraviolet radiation. Understanding UV levels helps you prevent sunburn and maintain skin health, ensuring you enjoy the island’s sun-soaked paradise safely. With a tropical climate that boasts high UV exposure, especially during midday hours—peaking at a staggering 13 between noon and 1 PM—it's essential to monitor the UV Index to safeguard your well-being while soaking in Ko Samui's stunning beaches and vibrant atmosphere.

Hourly UV Index in Ko Samui

As the sun climbs higher, the UV Index reaches its peak intensity around 12:00 PM, soaring to a striking 13—a clear signal for outdoor enthusiasts to take precautions. The morning hours start gently, with a low of 1 at 07:00 AM, gradually escalating to 6 by 09:00 AM and hitting 9 at 10:00 AM. By 11:00 AM, the sun begins to assert itself with a 12. However, as the afternoon progresses, the UV intensity starts to wane, dropping to 10 at 2:00 PM, and tapering off to a mere 2 by 5:00 PM. As daylight diminishes, the UV Index dwindles to 0 by 7:00 PM, inviting a much-needed respite from the sun’s relentless rays. Always be vigilant and protect your skin during those peak hours!

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
Time	UVI	Category	Time to Burn
07:00	1	low	45 min
08:00	3	moderate	30 min
09:00	6	high	25 min
10:00	9	very high	15 min
11:00	12	extreme	10 min
12:00	13	extreme	10 min
13:00	13	extreme	10 min
14:00	10	very high	15 min
15:00	7	high	25 min
16:00	4	moderate	30 min
17:00	2	low	45 min
18:00	1	low	45 min
19:00	0	low	45 min

Monthly UV Index Trends in Ko Samui

The UV Index exhibits remarkably high and consistent levels throughout the year, with extreme exposure ratings from January to November and a slight decline in December. The highest values occur between March and October, particularly peaking at 15 in March and April. Residents and visitors should be particularly cautious during these months, with an advised burn time of just 10 minutes before sun protection measures should be taken. January, February, and November follow closely with a UV Index of 11-14. To ensure safety, it is crucial to apply broad-spectrum sunscreen, wear protective clothing, and seek shade when outdoors during these high-risk months. Stay informed and protect your skin from harmful UV radiation year-round.

Monthly Maximum UV Index for Ko Samui, Thailand

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Ko Samui. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.

Data source: Statistical UV Index data for Ko Samui, based on information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

Compare Ko Samui UV Index with Other Thailand Cities

The table above highlights how UV exposure in Ko Samui compares to other major locations across Thailand. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.

Ko Samui's solar exposure compared to other cities in Thailand. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Mueang Nonthaburi UVI	10	12	14	13	14	13	14	14	13	12	9	8
Samut Prakan UVI	10	12	14	13	14	13	14	14	13	12	9	8
Bangkok UVI	10	12	14	13	14	13	14	14	13	12	9	8
Udon Thani UVI	9	11	13	14	14	13	14	14	14	12	10	9
Chon Buri UVI	10	13	14	14	14	13	14	14	13	13	10	9
Ko Samui	11	14	15	15	14	13	14	14	14	14	11	11