UV Index in San Jose, United States

Last updated: June 2, 2025

Understanding the UV Index in San Jose is crucial for protecting your skin and overall health while enjoying the beautiful California sunshine. With its Dfa climate, the region experiences high UV levels, particularly during midday, where values can soar to 11—indicating a very high risk of harm from unprotected sun exposure. Being aware of these levels helps you take essential precautions against sunburn and long-term skin damage. By keeping an eye on the UV Index, residents can fully embrace the outdoors while safeguarding their skin from potential risks associated with high UV exposure throughout the day.

Hourly UV Index in San Jose

The UV Index steadily climbs as the day progresses, starting from a mild 1 at 7:00 AM and reaching a peak of 11 by 1:00 PM. Sun-seekers and outdoor enthusiasts should be mindful, as the index hits a high of 10 at 12:00 PM, signaling significant UV exposure. After this peak, the index gradually decreases, dropping to 8 by 3:00 PM, and continuing to decline to 1 by 7:00 PM. For safe sun enjoyment, it’s best to take precautions during those high UV hours, particularly between 11:00 AM and 2:00 PM. Remember to sport your hats and sunscreen!

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.
TimeUVICategoryTime to Burn
07:001low45 min
08:002low45 min
09:004moderate30 min
10:006high25 min
11:009very high15 min
12:0010very high15 min
13:0011extreme10 min
14:0010very high15 min
15:008very high15 min
16:006high25 min
17:003moderate30 min
18:002low45 min
19:001low45 min

Monthly UV Index Trends in San Jose

Throughout the year, UV exposure fluctuates significantly, with the highest risk months being from March to September. Notably, April through June witness the peak UV Index values, reaching 11 in June, classified as extreme, where the burn time shortens to just 10 minutes. In contrast, the winter months of January and December show much lower risks, with UV Index levels at 3 and 2, respectively. Residents and visitors should take heed during the high-risk months by wearing protective clothing, applying sunscreen, and limiting sun exposure, especially during midday when the sun’s rays are most intense. Overall, staying vigilant about UV levels can help prevent skin damage and maintain health year-round.

Monthly Maximum UV Index for San Jose, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in San Jose. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec357810111098642
Data source: Statistical UV Index data for San Jose, 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 Jose UV Index with Other United States Cities

The table above highlights how UV exposure in San Jose compares to other major locations across United States. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.
San Jose's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
 JanFebMarAprMayJunJulAugSepOctNovDec
Chicago UVI34689101098642
Brooklyn UVI35681010998642
New York City UVI35681010998642
San Jose357810111098642
Los Angeles UVI46891011111010754
Houston UVI589111112121110975