Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors of Sun Valley, United States, where the beautiful mountain climate comes with unique sun exposure risks. As a Csb climate zone, Sun Valley experiences varying UV levels throughout the day, peaking at an extreme level of 11 around noon. Recognizing and tracking these UV levels is essential for preventing sunburn and protecting skin health, ensuring that everyone can enjoy the stunning outdoors safely. With the sun’s intensity fluctuating significantly, awareness of the UV Index helps you plan your activities wisely and safeguard your skin against harmful rays.
At dawn, the UV Index starts at a gentle 1 by 07:00, indicating minimal exposure risk. As the sun climbs higher, the intensity rises sharply, reaching a maximum of 11 between 12:00 and 13:00—a time when protective measures are crucial. The peak UV Index highlights the importance of sun safety, as conditions can be particularly harsh. The afternoon sees a gradual decline, dipping to 8 by 15:00 and further decreasing to 3 by 17:00. As evening approaches, the index wanes to a mellow 1 by 19:00, suggesting a return to safer exposure levels. Keep in mind that tracking the UV Index throughout the day can help protect your skin from harmful rays!
| 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 | 10 | 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 Index levels vary significantly, impacting the risk of skin damage from sun exposure. January starts with a moderate UV Index of 4, where burn time is generally 30 minutes, while February sees an increase to 6, classified as high, shortening burn time to 25 minutes. The high-risk months span from March to August, peaking in May and June with an extreme UV Index of 11-12, where burn time dramatically decreases to just 10 minutes. In September, the UV Index drops to 10, still considered very high, with a burn time of 15 minutes. As the year progresses into October, it falls to 7 (high), and finally stabilizes in November and December at indices of 4 and 3, respectively (moderate), allowing for longer burn times of 30 minutes. Visitors and residents are advised to take precautions such as wearing sunscreen, protective clothing, and seeking shade, especially during high-risk months when UV exposure is at its peak.
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 |
| Sun Valley | 4 | 6 | 8 | 9 | 11 | 12 | 12 | 11 | 10 | 7 | 4 | 3 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |