UV Index in San Jose, Costa Rica

Last updated: June 2, 2025

Understanding the UV Index in San Jose, Costa Rica is crucial for protecting your skin and overall health. With the region's tropical climate characterized by intense sunlight, the UV levels can spike dramatically, especially during midday. For instance, during peak hours, UV Index readings can reach an alarming 14, putting residents and visitors at risk for sunburn and long-term skin damage. Being aware of these levels not only helps in sunburn prevention but also plays a vital role in maintaining skin health. Knowing when to seek shade and apply sunscreen can make all the difference in enjoying the beautiful Costa Rican outdoors while keeping your skin safe.

Hourly UV Index in San Jose

As the day unfolds, the UV Index begins a steady climb, starting from a manageable 2 at 07:00. By 08:00, it jumps to 5, indicating a moderate risk of harm from unprotected sun exposure. The real intensity hits between 10:00 and 12:00, peaking at a staggering 14 at noon, urging caution as this signifies a high risk for skin damage without protection. While the intensity gradually decreases after this peak, it remains notable at 12 by 13:00. The afternoon sees a substantial drop, with readings of 8 at 14:00 before plummeting to 2 by 16:00. As evening approaches, the UV Index dwindles further, with values reaching a comfortable 0 by 19:00, signaling that the sun's hazardous rays have finally retreated for the day.

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	11	extreme	10 min
11:00	13	extreme	10 min
12:00	14	extreme	10 min
13:00	12	extreme	10 min
14:00	8	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