UV Index in San Jose, Costa Rica

Last updated: July 2, 2025

Understanding the UV Index in San Jose, Costa Rica, is essential for safeguarding your skin and overall health. With its tropical climate and high sun exposure, locals and visitors alike must be aware of UV levels to prevent sunburn and long-term skin damage. During peak hours, especially from 10 AM to 1 PM, San Jose experiences elevated UV indices—reaching as high as 14—indicating extreme risk of harm from unprotected sun exposure. By staying informed about the UV Index, you can enjoy the beautiful Costa Rican sun while taking the necessary precautions to protect your skin health.

Hourly UV Index in San Jose

As the sun rises, the UV Index starts off low at 2 at 07:00, perfect for a morning stroll. By 08:00, it climbs to 4, indicating a bit more sun exposure. The heat of the day peaks between 10:00 and 12:00, with the UV Index soaring to a striking 14 at 12:00. This is the time to take precautions! As the afternoon wanes, the index gradually declines, dropping to 9 by 14:00 and falling further to 5 at 15:00. By the evening, it’s safe to venture out again, with levels decreasing to a mere 0 by 18:00 and remaining so through the night. Stay sun-smart and enjoy the beautiful day while knowing when to seek shade!

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	13	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 Jose

The UV Index data reveals significant seasonal variations in ultraviolet radiation exposure, with the highest risk occurring from March through August, when the UV Index consistently reaches 14, categorized as extreme with a burn time of just 10 minutes. February sees a peak UV Index of 13, while September through November gradually taper to 11 and 10 respectively, though still in the extreme and very high categories. Visitors and residents should take precautionary measures during these high-risk months, including applying sunscreen, wearing protective clothing, and seeking shade to minimize the risk of skin damage. Even in the months of reduced intensity, such as December, vigilance is advised to protect against prolonged sun exposure.

Monthly Maximum UV Index for San Jose, Costa Rica

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

The table above highlights how UV exposure in San Jose 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 Jose'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
San Jose	11	13	14	14	14	14	14	13	13	13	11	10
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 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