Last updated: May 3, 2025
In the beautiful city of Denver, understanding the UV Index is essential for protecting your skin and overall health. With the sun’s rays striking at higher angles, particularly in the Dfa climate, residents and visitors alike must stay informed about fluctuating UV levels throughout the day. A UV Index that peaks at 9 during midday highlights the urgent need for sunburn prevention strategies to avoid immediate harm and preserve long-term skin health. Being aware of these levels can help you enjoy the Colorado sunshine responsibly, ensuring that outdoor adventures remain safe and enjoyable.
At 07:00, the UV Index begins at a mild 1, perfect for a leisurely morning stroll. As the sun rises higher, it gradually climbs to 2 by 08:00 and reaches 3 at 09:00. The intensity really kicks in at 10:00, jumping to 5, and soars to its peak of 9 by 13:00. This high exposure continues through 14:00, making midday the most crucial time for sun protection. As the afternoon wanes, the index dips to 7 at 15:00, then continues to decline to 5 at 16:00 and settles back to 3 by 17:00. The evening brings relief with a return to 2 by 18:00 and finally drops to 1 at 19:00. Make sure to stay protected during those peak hours!
| 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 | 7 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index demonstrates significant seasonal fluctuations, with high-risk months typically occurring from April to September. In April, the UV Index escalates to 8, indicating very high exposure risks, and remains elevated through May (9) and June (11), where it reaches an extreme level. July (10) and August (9) continue to present very high risks, before tapering off in September (8). As a precaution, visitors and residents should take protective measures, especially during these peak months, by seeking shade, wearing protective clothing, and applying sunscreen frequently. In contrast, the UV Index drops to a moderate level (3-5) from October to March, allowing for safer outdoor activities during this period.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Denver | 3 | 5 | 5 | 8 | 9 | 11 | 10 | 9 | 8 | 5 | 3 | 3 |
| 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 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |