Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in Denver, United States, especially given the city's elevated altitude and sunny climate. Staying informed about UV levels is essential for preventing sunburn and protecting skin health; higher index numbers indicate a greater risk of harmful effects from unprotected sun exposure. Typically experiencing a warm Cfa climate, Denver faces unique challenges with UV exposure, particularly during peak hours when the index often reaches 10—a level signifying a very high risk. By tuning into the daily UV Index, you can enjoy the beautiful Colorado sunshine while safeguarding your skin against its potentially damaging effects.
As the day unfolds, the UV Index begins its ascent with a gentle start at 1 from 07:00 to 08:00. By 09:00, it jumps to 3, signaling increased sun intensity. The real peak occurs between 12:00 and 14:00, where the index reaches a striking 10, reminding us to stay protected under the sun. Afterwards, the index gradually slips, dipping to 6 by 16:00, and further down to a mellow 1 by 19:00. It's crucial to be mindful of these fluctuations, especially during the midday hours when UV radiation poses the highest risk. Enjoy the rays but remember to stay safe!
| 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 | 10 | very high | 15 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 |
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 |