UV Index in San Diego, United States

Last updated: June 2, 2025

In sunny San Diego, awareness of the UV Index is essential for protecting your skin from harmful ultraviolet rays. Understanding UV levels is crucial for preventing sunburn and maintaining overall skin health, especially in a city known for its bright skies and outdoor lifestyle. With typical daytime values reaching as high as 12, San Diego residents and visitors are exposed to significant UV risks, particularly between 11:00 AM and 2:00 PM. Stay informed and take the necessary precautions to enjoy the sun safely!

Hourly UV Index in San Diego

As the sun rises, the UV Index starts at a mild 1 at 7:00 AM and remains low until 9:00 AM, where it climbs to 3. By 10:00 AM, the index accelerates to a moderate 5, but it’s at 11:00 AM that the heat intensifies, reaching 8. The peak occurs at 12:00 PM with a staggering value of 10, followed by the highest point of the day at 1:00 PM and 2:00 PM, where it maxes out at 12. After this peak, the index gradually declines: it drops to 10 by 3:00 PM and continues to decrease to 7 at 4:00 PM. By the late afternoon, the intensity wanes, falling to 5 at 5:00 PM and back down to 2 by 6:00 PM, before settling at 1 again as day turns to dusk by 7:00 PM. Remember to shield yourself during the midday hours when the UV radiation is at its most intense!

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
14:0012extreme10 min
15:0010very high15 min
16:007high25 min
17:005moderate30 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