Last updated: August 1, 2025
In Pomona, California, understanding the UV Index is essential for protecting your skin from harmful UV radiation. With peak UV levels reaching 10 between 1 PM and 2 PM on sunny days, awareness is crucial for sunburn prevention and long-term skin health. The city’s Cfa climate—characterized by hot summers—means residents and visitors are frequently exposed to UV rays, making it important to stay informed about daily UV levels. By monitoring the UV Index, you can take proactive steps to enjoy the sun safely while minimizing risks associated with excessive sun exposure.
During the day, the UV Index shows a notable rise, starting from a safe level of 1 at 07:00 and 08:00. As the sun climbs higher, it peaks at an intense 10 between 13:00 and 14:00, indicating a high risk of harm from unprotected sun exposure. Be cautious during this timeframe! The index gradually dips to 7 at 16:00, then falls to a more manageable 2 by 18:00, before returning to a minimal 1 as daylight wanes. For those planning outdoor activities, it's crucial to protect your skin during the midday hours when the sun is strongest.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, seasonal UV changes present varying risks for sun exposure. The high-risk months typically occur from April to August, when the UV Index rises to 9 or above, indicating very high to extreme exposure levels. Specifically, June and July see the most critical levels at 11, suggesting a burn time of just 10 minutes. Visitors and residents should be particularly vigilant during these months, applying sunscreen with a high SPF, wearing protective clothing, and seeking shade during peak sun hours. As the UV Index decreases from September to December, with values dropping back to 3-6, precautions remain advisable but can be somewhat relaxed, particularly in the winter months.
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 | 6 | 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 |