Last updated: July 2, 2025
In Williams, United States, being aware of the UV Index is crucial for protecting your skin from harmful effects of the sun. Understanding UV levels helps prevent sunburn and promotes long-term skin health, making it essential for everyone who enjoys the outdoors. With a climate characterized as Csb, Williams experiences varying UV exposure throughout the day, peaking at an index of 10 around midday. This highlights the importance of taking precautions during the sunniest hours to ensure your skin stays safe and healthy while enjoying all that nature has to offer.
The UV Index reveals a dynamic ascent and descent throughout the day, peaking with intensity during midday. Starting at a gentle 1 at 7:00 AM, it climbs steadily, reaching 10 by 1:00 PM and maintaining this highest level until 2:00 PM. This critical window indicates significant sun exposure, and it’s essential to take precautions. As the afternoon progresses, the index begins to taper off, dropping to 8 at 3:00 PM, then gradually falling to 1 by 7:00 PM. This data highlights the importance of being sun-smart during the peak hours to minimize UV exposure risks.
| 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 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 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, 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 |