UV Index in San Francisco, Peru

Last updated: June 2, 2025

Understanding the UV Index in San Francisco, Peru is essential for residents and visitors alike, as it plays a crucial role in preventing sunburn and protecting skin health. High UV levels can lead to serious skin issues, making it vital to be aware of daily sunlight exposure. With a climate marked by mild temperatures and varying UV risks throughout the day, San Francisco experiences peak UV readings of 11 around midday, indicating a very high risk of harm from unprotected sun exposure. By keeping informed about the UV Index, you can enjoy the sunny days of San Francisco while safeguarding your skin from long-term damage.

Hourly UV Index in San Francisco

The UV Index today peaked dramatically in the late morning, starting from a low of 1 at 07:00 and climbing to an impressive 11 by 12:00. This intense exposure reached its zenith at 11:00, where precautions were essential as the Index hit 10. As the afternoon progressed, the UV levels began to gradually decline, dropping to 4 by 15:00 and further down to a modest 2 by 16:00. By the evening, the sun had softened, bringing the UV Index back to 1 at 17:00, and ultimately fading to 0 by 18:00, when the day's light had nearly vanished. Make sure to stay protected during peak hours to enjoy the sunshine safely!

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	5	moderate	30 min
10:00	8	very high	15 min
11:00	10	very high	15 min
12:00	11	extreme	10 min
13:00	10	very high	15 min
14:00	7	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 Francisco

Throughout the year, the UV Index in this region remains consistently high, peaking at 17 during the winter months of January, February, and March, as well as again in November and October, all categorized as extreme exposure with a burn time of only 10 minutes. Other months like April (UV Index 16) and December (UV Index 16) also present significant risk. Although there is a slight decrease in the index during the summer months, it remains high, ranging from 11 to 13. Visitors and residents should take precautionary measures year-round, including wearing sunscreen, protective clothing, and sunglasses, especially during high-risk months when the UV Index exceeds 12 from April through November. Prioritizing skin protection is essential to prevent sunburn and potential long-term damage.

Monthly Maximum UV Index for San Francisco, Peru

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

The table above highlights how UV exposure in San Francisco 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 Francisco'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
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
San Francisco	17	17	17	16	13	11	12	13	15	17	17	16