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UV Index in San Francisco

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Today's UV index in San Francisco, United States United States will be up to 7.4, indicating a high level of sun exposure for the average person. Check the annual sun radiation in the city and our tips for today to make sure you're safe in the sun.


Today's tips

With San Francisco's UV index reaching 7.4, protect your skin from harm by staying in shade, wearing protective clothing, and applying SPF 30+ sunscreen every 2 hours between 10 a.m. and 4 p.m., when UV rays are strongest.

San Francisco's UV Index

The UV index in San Francisco remains relatively low throughout the year due to the city's cool, foggy climate. It rarely exceeds 6, which is considered moderate.

Weather Seasons

UV index

San Francisco has a Mediterranean climate, with cool, wet winters and dry summers. However, its coastal location and unique topography can result in microclimates, causing variable weather within the city. Fog is common, especially in the summer.

San Francisco's Climate

Compared to its region and neighboring countries, San Francisco is generally cooler and foggier. While much of California experiences hot, dry summers, San Francisco's summer temperatures are milder due to the marine influence. Countries like Mexico, further south, have significantly higher temperatures and less rainfall year-round.

Annual Sun Radiation

The chart below displays the average Shortwave Radiation Sum (MJ/m²) for each month of the last year in San Francisco. It's designed to provide you with a better understanding of the yearly weather and sun exposure.


* This page's content about the UV index in San Francisco (United States) is for educational and informational purposes only. The developers and data providers are not liable for the accuracy, reliability, or availability of the information. The information is not a substitute for professional medical advice, and the developers and data providers are not medical professionals. Seek advice from a qualified health provider for any medical concerns, and do not disregard medical advice or delay seeking it based on the information provided on this site.