Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors of Williams, Arizona, where the sun shines brightly, especially during peak hours. With UV levels reaching their highest between 11 AM and 1 PM, awareness of sun exposure is vital for preventing sunburn and promoting long-term skin health. Williams experiences a temperate climate (Csb), but even in these milder conditions, the risk of UV radiation can lead to significant skin damage if safety measures aren't taken. Stay informed about the UV Index to enjoy the outdoors safely while protecting your skin from harmful rays!
As the day unfolds, the UV Index rises steadily, peaking at 11 around 1 PM—a clear signal for sun protection. Starting from a low of just 1 at 7 AM, it escalates through the morning, hitting 8 by 11 AM. At 12 PM, the intensity reaches a significant 10, before slightly diminishing to 9 at 3 PM and tapering off rapidly in the afternoon. As the sun begins to set, the UV levels drop to 4 by 5 PM, finally settling back to 1 by 7 PM. With this clear UV trajectory, staying cautious during the peak hours, especially from 11 AM to 2 PM, is essential for skin safety. Don your sunscreen and enjoy the sun responsibly!
| 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 | 11 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 9 | 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, the UV Index exhibits significant seasonal variations, influencing sun exposure levels for visitors and residents. From January to February, UV levels are moderate (3-4) with a burn time of 30 minutes, making sun protection advisable, especially for prolonged outdoor activities. A notable increase occurs in March, with the index rising to 6 (high), and this trend continues through April (8, very high) and May (10, very high), where burn times decrease to just 15 minutes. The peak occurs in June with an extreme index of 11, followed by consistently very high levels of 10 in July and August. September shows a slight drop to 8 (very high), before tapering back to 6 (high) in October. The UV Index diminishes further in November (4, moderate) and December (2, low), where extended exposure is safer with burn times of 30 and 45 minutes, respectively. It is essential for everyone to practice sun safety during high-risk months, particularly from March to September, when the potential for skin damage is greatest. Regular use of sunscreen, protective clothing, and seeking shade during peak hours is strongly recommended to minimize UV exposure.
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 |
| Williams | 3 | 4 | 6 | 8 | 10 | 11 | 10 | 10 | 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 |