Last updated: May 3, 2025
In California, understanding the UV Index is crucial for protecting yourself from harmful solar radiation. As one of the sunniest states in the U.S., California experiences elevated UV levels, especially during midday hours where the index can soar to 10—a major risk for sunburn and long-term skin health issues. By staying informed about UV levels, residents and visitors can make better choices about sun exposure, ensuring they enjoy the beautiful California sunshine while safeguarding their skin. Whether you're hiking in the mountains or lounging at the beach, being UV aware is essential in this climate zone known for its warm summers and vibrant outdoor lifestyle.
The UV Index rises swiftly throughout the morning, starting from a low of 1 at 07:00 and climbing steadily to reach its peak of 10 at 13:00. As the sun reaches its zenith, the index hits 9 at 12:00, a clear reminder of the intense midday sun. After this high, the UV levels gradually decrease; by 15:00, they drop to 8 and continue to soften to 3 by 17:00, before safely settling back to a 1 at 19:00. It's essential to stay protected during those peak hours, particularly between 11:00 and 14:00, when the sun’s rays can be most dangerous. Remember to apply sunscreen and wear protective clothing to keep your skin safe while enjoying the outdoors!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences notable variations, with the highest risk months occurring from April to August. During this period, the UV Index peaks at 11 in June and July, categorizing these months as having extreme exposure levels with a burn time of just 10 minutes. In contrast, the lowest risk months are January and December, where the UV Index remains at 3, indicating a moderate risk with a burn time of 30 minutes. Visitors and residents are strongly advised to take precautions during peak months by applying sunscreen, wearing protective clothing, and seeking shade, particularly between 10 a.m. and 4 p.m. to minimize the risk of sunburn and skin damage.
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 |
| California | 3 | 5 | 7 | 9 | 10 | 11 | 11 | 10 | 9 | 7 | 4 | 3 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |