UV Index in National City, United States

Last updated: June 2, 2025

Understanding the UV Index in National City, United States, is crucial for safeguarding your skin and promoting overall health. As a popular destination with a Csa climate characterized by warm summers and mild winters, residents and visitors need to be aware of the sun's intensity to prevent sunburn and long-term skin damage. The UV levels in National City can soar, peaking at 11 around midday, which underscores the importance of checking the UV Index daily. By staying informed about UV exposure risks, you can enjoy the beautiful California sunshine while ensuring your skin remains protected and healthy.

Hourly UV Index in National City

As the sun rises, the UV Index gradually climbs, starting at a low level of 1 at 07:00 and reaching a modest 2 by 08:00. However, by mid-morning, it surges to an impactful 4 at 09:00 and continues to rise dramatically. Peak intensity occurs at 12:00 and 13:00, with a staggering index of 11, indicating a significant risk of harm from unprotected sun exposure. Following this high, the index begins its descent, dropping to 10 at 14:00 and tapering off to a moderate level of 6 by 16:00. As the day winds down, the UV Index settles back to a low 1 by 18:00 and maintains this level through the evening hours. It's a day where sun safety is paramount during the midday 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
08:002low45 min
09:004moderate30 min
10:007high25 min
11:009very high15 min
12:0011extreme10 min
13:0011extreme10 min
14:0010very high15 min
15:008very high15 min
16:006high25 min
17:003moderate30 min
18:001low45 min
19:001low45 min

Monthly UV Index Trends in National City

As the seasons change, so do the UV index levels, significantly impacting sun safety practices. January sees a moderate UV index of 4, allowing for 30 minutes of potential sun exposure. However, by February, the UV index rises to 6 (high), reducing safe burn time to 25 minutes. The risk escalates from March through July, with values peaking at 11 (extreme) during May and June, necessitating caution with just 10 minutes of safe exposure. August and September remain high at 10 (very high), with 15 minutes of burn time, before a gradual decline begins in October with a 7 (high) index. Throughout November and December, the index returns to a moderate 5 and 4, allowing for safe exposure up to 30 minutes. For both visitors and residents, it is crucial to be particularly vigilant during the high-risk months of March to September, taking proactive measures such as wearing sunscreen, protective clothing, and seeking shade during peak sun hours to safeguard against harmful UV radiation.

Monthly Maximum UV Index for National City, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in National City. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec468101111111010754
Data source: Statistical UV Index data for National City, 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 National City UV Index with Other United States Cities

The table above highlights how UV exposure in National City 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.
National City'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
National City468101111111010754
Houston UVI589111112121110975