UV Index in San Juan, Costa Rica

Last updated: July 2, 2025

Understanding the UV Index in San Juan, Costa Rica, is crucial for safeguarding your skin and overall health in this tropical paradise. With high UV levels peaking at 14 during midday hours, awareness of these fluctuations is essential for preventing sunburn and long-term skin damage. Costa Rica's warm climate and abundant sunshine create a beautiful but potentially hazardous environment for sun exposure, making it imperative to monitor UV levels daily. By staying informed, you can enjoy San Juan's stunning beaches and outdoor activities while keeping your skin safe from the sun's harmful rays.

Hourly UV Index in San Juan

The UV Index peaks dramatically during the midday hours, illustrating the sun's intensity in compelling detail. Starting at a modest 2 by 07:00, it swiftly ascends as the day unfolds. By 08:00, it jumps to 5, and then reaches a significant 8 at 09:00. The sun is at its fiercest between 10:00 and 12:00, with the index soaring to 14, an indication to take extra precautions! As 13:00 rolls around, the UV level dips slightly to 12, only to further decrease to 9 by 14:00. Post-midday, the sun's strength wanes; it dramatically drops to 5 by 15:00 and decreases to 1 by 17:00, finally settling at 0 by 19:00. Such data highlights the importance of sun protection during the peak hours when the UV intensity is at its highest.

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	2	low	45 min
08:00	5	moderate	30 min
09:00	8	very high	15 min
10:00	12	extreme	10 min
11:00	14	extreme	10 min
12:00	14	extreme	10 min
13:00	12	extreme	10 min
14:00	9	very high	15 min
15:00	5	moderate	30 min
16:00	2	low	45 min
17:00	1	low	45 min
18:00	0	low	45 min
19:00	0	low	45 min

Monthly UV Index Trends in San Juan

Throughout the year, UV radiation levels remain notably high, with an extreme UV Index ranging from 11 to 16. The months of January to April exhibit the highest UV exposure, peaking in April at an index of 16. This trend remains consistent until October, when a slight decrease occurs, yet October still holds a significant index of 15. November and December show a slight reduction in UV levels, but caution is still advised as the exposure remains extreme. Visitors and residents should be particularly vigilant from January to October, during which time burn time is limited to just 10 minutes. Protective measures such as wearing sunscreen, hats, and sunglasses are essential, especially during these high-risk months to prevent sunburn and long-term skin damage.

Monthly Maximum UV Index for San Juan, Costa Rica

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in San Juan. 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 San Juan, 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 San Juan UV Index with Other Costa Rica Cities

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

San Juan's solar exposure compared to other cities in Costa Rica. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Limon UVI	12	13	14	15	14	13	13	13	13	14	11	10
Liberia UVI	11	13	14	14	14	14	14	13	13	13	11	10
Alajuela UVI	12	13	15	15	14	14	14	13	13	14	12	10
San Juan	12	14	15	16	14	14	14	14	14	15	12	11
San Jose UVI	12	14	15	16	14	14	14	14	14	15	12	11
Paraiso UVI	13	14	16	16	15	15	15	14	14	15	12	11