UV Index in San Juan, Peru

Last updated: July 2, 2025

In San Juan, Peru, understanding the UV Index is crucial for safeguarding skin health and preventing sunburn, especially given the region's characteristic BWk climate. As the sun's rays can intensify, reaching peak levels of 9 between 11:00 AM and 1:00 PM, being aware of UV exposure is essential for daily outdoor activities. Recognizing these UV levels empowers residents and visitors to take proactive measures, ensuring that fun in the sun doesn't come at the cost of their skin’s well-being.

Hourly UV Index in San Juan

The UV Index on this particular day showcased a notable peak between 11:00 AM and 1:00 PM, reaching a high of 9, indicating a very high level of UV radiation. Early risers at 7:00 AM were greeted with a modest index of 1, but as the sun climbed higher, the intensity increased dramatically. At 10:00 AM, the index hit 6, solidifying the day's progression towards its maximum. After the midday zenith, the UV levels began to decline, dropping back to 4 by 3:00 PM and tapering off further, ultimately reaching 0 by 7:00 PM. This pattern highlights the importance of sun safety, particularly during the peak hours when UV exposure poses the greatest risk.

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	1	low	45 min
08:00	2	low	45 min
09:00	4	moderate	30 min
10:00	6	high	25 min
11:00	9	very high	15 min
12:00	9	very high	15 min
13:00	9	very high	15 min
14:00	6	high	25 min
15:00	4	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 index levels show significant seasonal variation, with extreme exposure categories prevalent from January to April and again in August and November. The highest-risk months for UV exposure are January, February, and November — all with a UV index of 15 and a burn time of just 10 minutes. From March to April, the index remains high but slightly decreases to 14 and 13, respectively. Visitors and residents are strongly advised to take precautions during these critical months, including wearing protective clothing, seeking shade, and applying high SPF sunscreen to reduce the risk of sunburn and long-term skin damage. In contrast, from May through July, while the UV index remains high, exposure risks lessen slightly, with burn times extending to 15 minutes. However, vigilance is still necessary, especially during peak sunlight hours.

Monthly Maximum UV Index for San Juan, Peru

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 Peru Cities

The table above highlights how UV exposure in San Juan compares to other major locations across Peru. 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 Peru. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Callao UVI	14	14	14	12	10	9	10	11	12	13	14	13
Lima UVI	14	14	14	12	10	9	10	11	12	13	14	13
San Juan	15	15	14	13	10	9	9	11	13	14	15	15
Trujillo UVI	15	15	15	14	12	11	11	11	13	14	14	14
Chiclayo UVI	14	15	15	14	13	11	11	12	15	14	14	13
Arequipa UVI	18	17	17	15	12	10	11	13	15	17	18	17