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 maintaining overall health. With UV levels peaking at an intense 15 during midday, it's important to be aware of this metric to prevent sunburn and long-term skin damage. San Francisco’s BSk climate means sunny days can present heightened exposure risks, particularly from late morning to mid-afternoon. By staying informed about UV levels, you can enjoy the sun safely and keep your skin healthy throughout the year.

Hourly UV Index in San Francisco

As the sun rises, the UV Index starts off modestly, peaking at 1 by 8:00 AM. However, as the day progresses, it experiences a dramatic surge. Expect a notable climb by 10:00 AM, hitting 5, and then reaching its zenith at 1:00 PM with an impressive 15. The intensity remains high throughout the afternoon, only slightly easing towards the evening. By 6:00 PM, the index drops to 3, and settles back to 1 by 7:00 PM. It's a reminder to stay sun-safe during peak hours, especially from 11:00 AM to 2:00 PM, when the UV radiation is 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	1	low	45 min
08:00	1	low	45 min
09:00	2	low	45 min
10:00	5	moderate	30 min
11:00	9	very high	15 min
12:00	13	extreme	10 min
13:00	15	extreme	10 min
14:00	15	extreme	10 min
15:00	13	extreme	10 min
16:00	10	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 high-risk months spanning from February to October. During this period, the UV Index reaches extreme levels, peaking at 15 in April and May. Notably, March to October maintains an extreme exposure category where the burn time is as short as 10 minutes. The highest risk for sunburn occurs in early months like February (UV Index 11) and peaks from March to May, where visitors and residents should exercise extreme caution. In contrast, November and December present lower UV Index values categorized as very high (9-10), allowing for slightly longer safe exposure times (15 minutes). To minimize skin damage and health risks, it is advised for individuals to seek shade, wear protective clothing, and apply sunscreen, especially during the peak UV hours from late morning to early afternoon.

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	15	15	14	14	14	14	13	10	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