UV Index in San Francisco, Peru

Last updated: June 2, 2025

Understanding the UV Index is crucial for maintaining skin health in San Francisco, Peru. Due to its unique placement in a BWh climate zone, this region experiences varying UV levels throughout the day, with significant peaks around midday. Awareness of UV levels not only aids in preventing sunburn but also helps mitigate long-term skin damage. For residents and visitors alike, recognizing that the UV Index can soar to levels as high as 10 means taking proactive sun protection measures, especially during peak hours. Stay informed and safeguard your skin!

Hourly UV Index in San Francisco

As the sun rises, the UV Index begins its climb, starting at a modest 1 at 07:00. By 08:00, it gently increases to 2, signaling a day of strengthening rays. The intensity peaks around 12:00 with a striking 10, indicating the time for caution and sun protection. As midday passes, the index gradually declines, dropping to 6 at 14:00 before continuing its descent to 4 at 15:00. By 17:00, it returns to a safer 1, and eventually fades to 0 after 18:00, marking a gentle close to the day. This data underscores the importance of seeking shade and wearing sunscreen during the midday hours when the UV exposure is at its most intense.

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	7	high	25 min
11:00	9	very high	15 min
12:00	10	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 Francisco

The UV Index shows significant seasonal variation, with extreme levels persisting from January to April and notable spikes returning in the fall months of September, October, and November. The high-risk months (with a UV Index of 15 or higher) are January through April and November, indicating a consistent risk for sunburn with a burn time as short as 10 minutes during these periods. Even in the summer months of June through August, options remain elevated but shift slightly to very high, allowing a slightly longer exposure of 15 minutes in June before returning to a 10-minute burn time. Visitors and residents should exercise caution, particularly during high UV Index periods, by wearing protective clothing, applying broad-spectrum sunscreen, and seeking shade during peak hours to minimize skin damage and health risks.

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
San Francisco	15	16	15	14	11	10	11	12	14	15	16	15
Arequipa UVI	18	17	17	15	12	10	11	13	15	17	18	17