Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors of San Diego, where sunny skies and warm temperatures create a picturesque coastal paradise. With UV levels frequently reaching dangerous highs—topping out at 11 during midday—awareness of these factors is vital for protecting your skin against sunburn and long-term damage. San Diego's BSk climate means that while you can enjoy outdoor activities year-round, you also face greater exposure risks from ultraviolet radiation. Stay informed about the UV Index to safeguard your health and relish the sun responsibly!
The UV Index demonstrates a clear peak in intensity throughout the day, showcasing the need for sun protection during certain hours. Starting from a low of 1 at 07:00, the index rises steadily, reaching 4 by 09:00, before surging to a powerful 11 at midday. This intense level of UV radiation persists until 13:00, emphasizing the risk during these prime hours. As the afternoon progresses, the index gracefully declines, registering 9 at 14:00 and tapering off to a more moderate 3 by 17:00. By evening, it drops back to 1, signaling a safe window for outdoor activities as the sun sets. Be mindful of these fluctuations and stay protected during peak hours!
| 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 | 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 | 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 |
| San Diego | 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 |