Last updated: May 3, 2025
Awareness of the UV Index is crucial for residents of Pomona, California, given its warm Cfa climate that often brings intense sunlight. Understanding UV levels not only aids in preventing sunburn but also plays a significant role in maintaining overall skin health. During peak hours, such as noon to 1 PM, the UV Index can reach values as high as 10, indicating a very high risk of harm from unprotected sun exposure. With Pomona's frequent and potent UV radiation, it's essential to stay informed and protected to enjoy the beautiful California weather safely.
As the sun rises, the UV Index gradually climbs, starting at a modest 1 at 7:00 AM and reaching an energetic 2 by 8:00 AM. The intensity escalates quickly, peaking at a robust 10 between 12:00 PM and 1:00 PM—the ideal time to take extra sun safety precautions! By 2:00 PM, the index begins its gentle decline, settling to 9 at 2:00 PM, and gradually tapering off to a more manageable 3 by 5:00 PM. As evening approaches, the index dwindles to 1 by 6:00 PM, allowing for a calm end to the day. Remember, during peak hours, it’s crucial to protect your skin to enjoy the sunshine safely!
| 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 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | very high | 15 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 |
Throughout the year, the UV Index experiences significant seasonal fluctuations, with high-risk months primarily occurring from March to September. During these months, the UV Index peaks at 10, indicating a very high exposure category, which corresponds to a burn time as brief as 15 minutes. In contrast, the UV Index drops to moderate levels of 3 in January and December, allowing for a safer exposure duration of 30 minutes. To ensure safety, visitors and residents should take precautions, especially during the high-risk months by seeking shade, wearing protective clothing, and applying sunscreen regularly. As the UV Index lessens after September, the risk of skin damage declines significantly, but caution should still be practiced in October.
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 |
| Pomona | 3 | 5 | 6 | 8 | 10 | 10 | 10 | 10 | 8 | 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 |