UV Index in San Diego, United States

Last updated: May 3, 2025

Understanding the UV Index in San Diego is crucial for anyone looking to enjoy the sun safely in this beautiful coastal city. With its Cfa climate delivering plenty of sunshine, awareness of UV levels can help prevent sunburn and long-term skin damage. The daily UV Index fluctuations—from a moderate level of 3 in the morning to a peak of 12 at noon—highlight the risks associated with UV exposure, especially during peak hours. Staying informed not only supports skin health but also enhances your overall outdoor experience in San Diego, where sun-soaked days beckon year-round.

Hourly UV Index in San Diego

The day begins gently with a UV Index of 1 at both 07:00 and 08:00, indicating minimal sun exposure. However, as the clock strikes 09:00, the index rises to 3, signifying a gradual increase in UV intensity. By 10:00, it reaches 5, and the sun takes center stage at 11:00 with a striking 8. The peak arrives at 12:00, soaring to an impressive 10, and continues to climb, hitting its pinnacle with a dazzling 12 at 13:00. As the afternoon unfolds, values begin a slow descent: 11 at 14:00, 10 at 15:00, and then dropping to 7 by 16:00. The evening brings relief, with the index tapering down to 4 at 17:00, 2 at 18:00, and finally returning to a safe 1 by 19:00. Remember to stay protected during those peak hours!

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
08:001low45 min
09:003moderate30 min
10:005moderate30 min
11:008very high15 min
12:0010very high15 min
13:0012extreme10 min
14:0011extreme10 min
15:0010very high15 min
16:007high25 min
17:004moderate30 min
18:002low45 min
19:001low45 min

Monthly UV Index Trends in San Diego

Throughout the year, UV Index levels fluctuate significantly, with the highest readings occurring in the summer months. From May to August, the UV Index reaches an extreme level of 12, posing the greatest risk for sunburn, with a minimal safe exposure time of just 10 minutes. April and September also see high values, with an index of 11. Visitors and residents are advised to take extra precautions during these high-risk months, such as applying sunscreen, wearing protective clothing, and seeking shade during peak sun hours. Conversely, in the winter months, from December to February, UV levels are lower, ranging from moderate to very high, but individuals should remain vigilant, especially in February and March when the index peaks at 8 and 10. Overall, awareness and protection against UV radiation are essential year-round, particularly during the hotter months.

Monthly Maximum UV Index for San Diego, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in San Diego. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec6810111212121211975
Data source: Statistical UV Index data for San Diego, 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 Diego UV Index with Other United States Cities

The table above highlights how UV exposure in San Diego 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 Diego'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
Los Angeles UVI46891011111010754
Houston UVI589111112121110975
San Diego6810111112121211975