UV Index in San Francisco, Mexico

Last updated: May 3, 2025

Understanding the UV Index in San Francisco, Mexico, is crucial for protecting your skin and overall health under the sun. The UV Index measures the strength of ultraviolet (UV) radiation, helping residents and visitors alike to be vigilant against sunburn and long-term skin damage. With a Mediterranean climate characterized by warm summers and cooler, foggy winters, the city's UV exposure can be deceptively high, particularly between late morning and early afternoon. On sunny days, be aware of elevated UV levels, peaking at 13 around midday, making sun safety practices essential for all outdoor activities. Stay informed and enjoy the sunny splendor while protecting your skin!

Hourly UV Index in San Francisco

The UV Index throughout the day showcases a dynamic shift in sun intensity. Starting at a low 0 at 7:00 AM, the index gradually climbs, reaching a moderate 2 by 9:00 AM. However, the sun's strength peaks dramatically at 13 between 1:00 PM and 2:00 PM, indicating a very HIGH level of UV radiation—ideal conditions for seeking shade or applying sunscreen. As the afternoon winds down, the index dips to a more manageable 5 by 5:00 PM, and finally settles at 1 by 7:00 PM. For sun seekers, midday offers the most intensity, so planning outdoor activities accordingly can help ensure both enjoyment and safety!

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	8	very high	15 min
12:00	11	extreme	10 min
13:00	13	extreme	10 min
14:00	13	extreme	10 min
15:00	12	extreme	10 min
16:00	9	very high	15 min
17:00	5	moderate	30 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