UV Index in San Marcos, Costa Rica

Last updated: July 2, 2025

Understanding the UV Index in San Marcos, Costa Rica, is essential for anyone looking to enjoy the lush landscapes and vibrant culture while safeguarding their skin health. The UV levels here can soar, peaking at 15 around noon, making it crucial to monitor these readings to prevent sunburn and long-term skin damage. With a tropical climate that typically produces high UV exposure, residents and visitors alike must stay informed to ensure a safe outdoor experience. By knowing when the sun's rays are most intense, you can protect your skin and enjoy everything this beautiful region has to offer without the worry of sun-related harm.

Hourly UV Index in San Marcos

At sunrise, the UV Index starts off low at 2 by 7:00 AM, but as the sun ascends, the intensity rapidly increases. By 8:00 AM, it reaches 5, and by 9:00 AM, it surges to 8. The peak occurs at 12:00 PM when the index hits a striking 15, indicating a high risk of harm from unprotected sun exposure. As the afternoon progresses, there’s a noticeable decline; by 2:00 PM, it's down to 9, then further diminishes to 5 at 3:00 PM. The sun sets, and by 6:00 PM, the UV Index drops to 0, signaling an end to the day's harmful rays. It's a reminder to stay sun-safe during those prime 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	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	15	extreme	10 min
13:00	13	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 Marcos

Throughout the year, UV levels remain consistently high, with an extreme exposure category noted across all months. The highest UV Index values occur from March to May, peaking at 16 in April, making this spring period particularly risky for sun exposure. Visitors and residents should be aware that the burn time remains a swift 10 minutes throughout the year, regardless of month. Therefore, it is crucial to take protective measures such as wearing sunscreen, protective clothing, and seeking shade, especially during the peak UV months from March to May. Stay vigilant and prioritize sun safety to minimize the risk of harmful UV exposure.

Monthly Maximum UV Index for San Marcos, Costa Rica

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

The table above highlights how UV exposure in San Marcos 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 Marcos'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 Jose UVI	12	14	15	16	14	14	14	14	14	15	12	11
San Marcos	12	14	15	16	15	14	15	14	14	14	12	11
Paraiso UVI	13	14	16	16	15	15	15	14	14	15	12	11