Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Cheyenne, United States, where the sun's rays can be particularly intense due to the high elevation and semi-arid climate. With UV levels reaching a peak of 12 around midday, knowing the UV Index empowers you to take necessary precautions to prevent sunburn and protect your skin health. As summer brings longer days and increased outdoor activity, being aware of UV levels can help you enjoy the sunshine safely, minimizing the risks of skin damage and other health issues associated with high UV exposure. Stay informed and make sun safety a priority in Cheyenne!
Throughout the day, the UV Index displayed a dynamic pattern, peaking at an intense 12 around 1 PM. Starting off gently at 1 by 7 AM, it climbed steadily, reaching 9 by 11 AM, a clear sign to take precautions. As the sun approached its zenith, the index swelled to its maximum at 12 PM, emphasizing the importance of sun safety. Following the midday peak, the index gradually decreased, dropping to 9 by 3 PM, then tapering off further to 2 by 6 PM and 1 by 7 PM. This data underscores the significance of shielding oneself from the sun's harmful rays during the day, especially when the UV Index is at its highest.
| 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 | 12 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 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 experiences notable fluctuations, with the highest risk months typically occurring from April to August. During this period, the UV Index reaches levels classified as very high to extreme, particularly peaking at 12 in June and July, which corresponds to a burn time of just 10 minutes. In contrast, the winter months of January, November, and December show a much lower UV Index, remaining in the moderate category at 4, allowing for a burn time of 30 minutes. As such, it is crucial for visitors and residents to be particularly vigilant about sun protection—especially in late spring and summer. Sunscreen, protective clothing, and seeking shade during peak hours are highly recommended to mitigate harmful effects from exposure during high UV Index periods.
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 |
| Cheyenne | 4 | 6 | 7 | 10 | 10 | 12 | 12 | 11 | 9 | 6 | 4 | 4 |
| 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 |