UV Index in San Francisco, Mexico

Last updated: June 2, 2025

Awareness of the UV Index in San Francisco, Mexico is crucial for safeguarding your skin, especially in a region where sunny days can quickly lead to high UV exposure. Understanding the UV levels is essential for preventing sunburn and maintaining overall skin health, as even brief moments in the sun can be harmful. San Francisco’s BWh climate boasts plenty of sunshine, with UV Index levels soaring to a peak of 12 during midday, indicating a high risk of harm from unprotected sun exposure. Stay informed and take the necessary precautions to enjoy the sun safely!

Hourly UV Index in San Francisco

As the sun rises, the UV Index begins its ascent, starting at a modest 1 by 07:00 AM. The intensity gradually increases, reaching 3 at 09:00 AM and surging to 5 by 10:00 AM. The peak of the day arrives with a striking 12 at both 1:00 PM and 2:00 PM, indicating a high risk for unprotected skin. By 3:00 PM, the index begins to decline, dropping to 10, then tapering off to 5 around 5:00 PM. As evening approaches, the UV Index cools down to 1 by 7:00 PM, suggesting a much safer environment for outdoor activities. Stay protected during those peak afternoon hours when the sun's rays are 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	1	low	45 min
09:00	3	moderate	30 min
10:00	5	moderate	30 min
11:00	8	very high	15 min
12:00	11	extreme	10 min
13:00	12	extreme	10 min
14:00	12	extreme	10 min
15:00	10	very high	15 min
16:00	8	very high	15 min
17:00	5	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in San Francisco

Throughout the year, UV exposure varies significantly, with high-risk months typically spanning from February to September, when the UV Index reaches very high and extreme levels. Particularly alarming is April to September, where the UV Index consistently registers at 12, indicating extreme risk with a minimal recommended burn time of just 10 minutes. In contrast, January and November present a high exposure risk with burn times of 25 minutes, while December sees a moderate risk with a more manageable 30 minutes. Consequently, it is essential for both visitors and residents to take precautions during peak UV months by wearing protective clothing, applying broad-spectrum sunscreen, and limiting time outdoors, especially during midday hours when UV rays are most potent.

Monthly Maximum UV Index for San Francisco, Mexico

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 Mexico Cities

The table above highlights how UV exposure in San Francisco compares to other major locations across Mexico. 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 Mexico. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
San Francisco	6	8	10	12	12	12	12	12	12	9	7	5
Guadalajara UVI	9	11	14	14	14	13	13	13	13	12	9	8
Iztapalapa UVI	10	12	14	15	14	14	14	14	14	12	10	8
Ecatepec de Morelos UVI	10	12	14	15	15	14	14	13	14	12	10	8
Mexico City UVI	10	12	14	15	15	14	14	13	14	12	10	8
Puebla UVI	10	12	14	15	15	15	15	14	14	13	10	9