Last updated: June 2, 2025
Understanding the UV Index in the United States is crucial for protecting your skin and overall health, especially as you navigate the changing seasons. In regions with a Cfa climate, like those with four distinct seasons, the sun's intensity can vary dramatically, emphasizing the need to monitor UV levels throughout the year. Being aware of the UV Index not only helps you prevent painful sunburns but also fosters long-term skin health by reducing the risks of skin cancer. With values peaking at 11 during midday hours in summer, it's essential to stay informed about UV exposure risks to enjoy all four seasons safely.
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 |
As the seasons change, so do the UV Index levels, which pose varying risks for sun exposure. January and December maintain moderate UV levels (3), allowing for a burn time of 30 minutes, while February sees a slight increase to 5. March marks the onset of higher risks with a UV index of 7, categorized as high, and a reduced burn time of 25 minutes. The months of April and May reach an alarming UV index of 10, labeled as very high, where burn time drops to just 15 minutes. The peak of danger occurs during June and July, with an extreme UV index of 11, demanding caution with an even shorter burn time of 10 minutes. August and September continue to present significant risks, both at a UV index of 10 and 9, respectively. As the year winds down, October sees a decrease to a high level of 7, while November and December return to moderate levels. Visitors and residents should prioritize sun protection during the high-risk months of March through September, especially during the peak summer months of June and July, by wearing sunscreen, protective clothing, and seeking shade during peak hours to prevent skin damage.
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 |
| Four Seasons | 3 | 5 | 7 | 10 | 10 | 11 | 11 | 10 | 9 | 7 | 5 | 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 |