Last updated: June 2, 2025
In Denver, United States, staying informed about the UV Index is crucial for protecting your skin and overall health. High UV levels can lead to sunburn and increase the risk of skin cancer, making it essential to understand when to seek shade or apply sunscreen. Denver's Cfa climate means plenty of sunny days, but the region's high elevation amplifies UV exposure, particularly during peak hours from 11 AM to 2 PM, when the UV Index can soar to levels of 10 or higher. Being aware of these fluctuations can help you enjoy the outdoors safely while prioritizing your skin's health.
The UV Index for the day showcases a striking pattern, starting moderate at 7:00 AM with a value of 1. As the sun climbs higher, the index steadily rises, hitting 3 by 9:00 AM, and then surging to a peak of 11 between 1:00 PM and 2:00 PM. This indicates a high risk of harm from unprotected sun exposure during midday. Following the peak, the UV Index gradually declines to 4 by 5:00 PM and further decreases to 1 by 7:00 PM, emphasizing the critical importance of sun protection during the intense midday hours. It’s advisable to seek shade and wear sunscreen if you're outside during the peak period!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 7 | 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 variations, with high-risk months occurring from March to August, where the index reaches very high to extreme levels. In March and April, the UV Index peaks at 10, and it escalates to 11 in June and July, indicating an urgent need for sun protection since the burn time drops to just 10 minutes during these months. The risk decreases in the fall and winter, with November and December showing moderate levels (UV Index of 5 and 3, respectively) and extended burn times of 30 minutes. To ensure safety, visitors and residents are advised to take extra precautions during the high-risk months by wearing sunscreen, protective clothing, and seeking shade, while enjoying outdoor activities to minimize the risk of 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 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Denver | 4 | 6 | 8 | 10 | 10 | 11 | 11 | 10 | 9 | 8 | 5 | 3 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |