UV Index in San Juan, Costa Rica

Last updated: July 2, 2025

Understanding the UV Index in San Juan, Costa Rica is crucial for protecting your skin and overall health during those sun-soaked days. With the region's warm, tropical climate, UV exposure can peak significantly, especially between 10:00 AM and 2:00 PM, where values hit as high as 14. Being aware of these levels helps you take preventive measures against sunburn and long-term skin damage, ensuring you enjoy the beauty of San Juan safely. From morning walks to afternoon adventures, keeping an eye on the UV Index can make all the difference in your sun safety routine.

Hourly UV Index in San Juan

The UV Index reveals a dramatic rise in sunlight intensity throughout the morning, peaking at an impressive 14 between 11:00 AM and 12:00 PM. This indicates a time when sun protection is vital, especially as it climbs swiftly from 2 at 07:00 AM to reach 8 by 09:00 AM, illustrating the day’s rapid increase in UV exposure. As the afternoon progresses, the index starts to decline, dropping to 5 at 3:00 PM before diminishing further to 1 by 5:00 PM and finally reaching 0 after 6:00 PM. Thus, the midday hours present the highest risk, calling for caution and proper sun safety measures!

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	4	moderate	30 min
09:00	8	very high	15 min
10:00	11	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, the UV Index reflects consistently high levels of ultraviolet radiation, particularly from January to October where the index remains in the extreme category, peaking at 15 in both March and April. This means that residents and visitors should be particularly vigilant during these high-risk months, as the burn time for unprotected skin is only 10 minutes across most of this period. As the year progresses, November and December experience slightly lower UV levels, but caution is still advised, especially as November has a UV Index of 12 (extreme) and burn time of 10 minutes, while December dips to 10 (very high) with a longer burn time of 15 minutes. It is essential for everyone to take protective measures, including wearing sunscreen, hats, and protective clothing, regardless of the season, to minimize the risk of 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
San Juan	12	13	15	15	14	14	14	13	13	14	12	10
Alajuela UVI	12	13	15	15	14	14	14	13	13	14	12	10
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