Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in National City, California, where the Mediterranean climate can lead to intense sun exposure. As UV levels rise throughout the day, particularly peaking between 11 AM and 1 PM with values reaching as high as 11, being aware of these levels is essential for preventing sunburn and protecting skin health. With the city's ample sunshine, it's important to proactively manage your sun safety to avoid harmful effects. By learning about UV exposure risks and protective measures, you can enjoy the beautiful National City climate while safeguarding your skin for years to come.
The UV Index for the day presents a fascinating variation as the sun climbs higher in the sky. Starting from a gentle 1 at 07:00, the intensity gradually escalates, reaching a moderate 4 by 09:00. The peak hits at 12:00 and 13:00, soaring to an intense 11, indicating a significant risk of harm from unprotected sun exposure. As the afternoon unfolds, the index begins to decline, tapering to 8 at 15:00, and by the evening, it plummets back to a 1 by 18:00. This data serves as a reminder to stay vigilant about sun safety during those peak hours when UV exposure is at its highest!
| 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 | 7 | high | 25 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
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.
UV Risk Categories
| 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 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| National City | 4 | 6 | 8 | 10 | 11 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |