UV Index in San Jose, United States

Last updated: May 3, 2025

Staying informed about the UV Index in San Jose is crucial for protecting your skin and overall health. With maximum UV levels reaching 10 in the midday sun, understanding these levels can help you prevent painful sunburns and long-term skin damage. San Jose's Dfa climate delivers plenty of sunshine, which, while enjoyable, also increases exposure risks. By being aware of the UV Index, you can take proactive steps to safeguard yourself and enjoy the outdoors safely.

Hourly UV Index in San Jose

As the sun rises, the UV Index starts its ascent, with a gentle 1 at 07:00. By 08:00, it begins to climb, reaching 2, signaling a reminder to take care. The real intensity kicks in at 10:00, where the index peaks at 6, escalating to a scorching 9 by noon. The hottest moment arrives at 13:00, showcasing a dramatic 10—a level that demands serious sun protection. Although the UV level begins to drop after this peak, it remains notable; at 14:00, it settles at 9, then declines gently, hitting 3 by 17:00. As daylight fades towards the evening, it tapers off to 2 at 18:00 and finally returns to a safe 1 by 19:00. It's a vivid reminder of the sun's power throughout the day!

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	2	low	45 min
09:00	4	moderate	30 min
10:00	6	high	25 min
11:00	8	very high	15 min
12:00	9	very high	15 min
13:00	10	very high	15 min
14:00	9	very high	15 min
15:00	7	high	25 min
16:00	5	moderate	30 min
17:00	3	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 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.

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.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Chicago UVI	3	4	6	8	9	10	10	9	8	6	4	2
Brooklyn UVI	3	5	6	8	10	10	9	9	8	6	4	2
New York City UVI	3	5	6	8	10	10	9	9	8	6	4	2
San Jose	3	5	7	8	10	11	10	9	8	6	4	2
Los Angeles UVI	4	6	8	9	10	11	11	10	10	7	5	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5