UV Index in San Francisco, Mexico

Last updated: July 2, 2025

Understanding the UV Index in San Francisco is essential for protecting your skin and overall health in this vibrant coastal city. With UV levels peaking around midday, reaching a maximum of 13, awareness can significantly help in preventing sunburn and long-term skin damage. San Francisco's Csa climate, characterized by mild, wet winters and dry summers, may lead to unexpected intensity in UV exposure. It's crucial to stay informed about local UV conditions, ensuring you enjoy the sunshine responsibly!

Hourly UV Index in San Francisco

As the day unfolds, the UV Index rises steadily, beginning at a safe 0 at 07:00 and peaking dramatically. By 10:00, it escalates to 4, signaling the need for some sun protection. The intensity reaches 10 at 12:00, and then hits its maximum at 13:00 with a formidable 12. Right after, it slightly dips but remains high at 12 until 15:00. As the afternoon wanes, the UV Index begins to decline, dropping to 9 by 16:00, and continuing its descent to 1 by 19:00. This fluctuation highlights the importance of being sun-smart during peak hours, especially between 11:00 and 15:00, when the sun is at its strongest.

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	0	low	45 min
08:00	1	low	45 min
09:00	2	low	45 min
10:00	4	moderate	30 min
11:00	7	high	25 min
12:00	10	very high	15 min
13:00	12	extreme	10 min
14:00	13	extreme	10 min
15:00	12	extreme	10 min
16:00	9	very high	15 min
17:00	6	high	25 min
18:00	3	moderate	30 min
19:00	1	low	45 min

Monthly UV Index Trends in San Francisco

Throughout the year, the UV Index experiences significant fluctuations, with the highest risk months occurring from February to September, when the index reaches extreme levels of 11 to 14 and requires minimal exposure times of just 10 minutes to avoid sunburn. In contrast, the months of November and December see the UV Index drop to 9 and 8 respectively, categorized as very high with longer burn times of 15 minutes. Residents and visitors are advised to take extra precautions during the peak months, such as wearing sunscreen, protective clothing, and seeking shade during peak sun hours, to safeguard against harmful UV radiation.

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
Guadalajara UVI	9	11	14	14	14	13	13	13	13	12	9	8
San Francisco	9	11	14	14	14	14	13	13	14	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