Last updated: July 2, 2025
As residents and visitors in Sun Valley, understanding the UV Index is crucial for enjoying the outdoors safely and maintaining your skin health. The UV Index measures solar radiation levels, helping you gauge the risk of sunburn and long-term skin damage throughout the day. With the typical Dfb climate of Sun Valley, which includes warm summers and plenty of sunny days, UV exposure can be significant. During peak hours, particularly from 10 AM to 2 PM, the UV Index can soar to dangerous levels, highlighting the importance of staying informed and protected against harmful rays.
At 07:00 AM, the UV Index starts off mild at 1, making it a safe time to enjoy the morning light. As the day progresses, the sun climbs higher, and by 10:00 AM, the index jumps to 6, signaling a notable increase in solar intensity. The peak of the day arrives at 01:00 PM, with a strong UV Index of 10—perfect for sun protection or seeking shade. Following this zenith, the index gradually declines, reaching 9 at 02:00 PM and tapering off to 3 by 05:00 PM, where it's still wise to stay cautious. As evening approaches, the UV Index drops further to 1 by 07:00 PM, allowing for a relaxed end to the day. Remember to stay safe and protect your skin during the most intense daylight hours!
| 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 | 6 | high | 25 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, UV exposure varies significantly, peaking during late spring and summer months. High-risk months for UV exposure are April through September, where the UV Index frequently reaches levels classified as very high; particularly notable are May, June, and July, when it consistently hits a maximum of 10. Visitors and residents are advised to take precautions during these months, with burn times dramatically reduced to as little as 15 minutes. In contrast, January, February, and November present moderate UV levels, and December has a low index, making sun safety measures less critical during these months. To protect against skin damage, it is essential to wear sunscreen, seek shade, and wear protective clothing, especially between peak months of April and September.
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 |
| Sun Valley | 3 | 5 | 6 | 9 | 10 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| 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 |