Last updated: July 2, 2025
Awareness of the UV Index is crucial for residents of Littleton, United States, as it plays a vital role in protecting skin health and preventing sunburn. Understanding UV levels not only helps you plan your outdoor activities but also safeguards against long-term skin damage. Littleton's climate, characterized by its Cfa classification, brings about varying UV exposure risks, particularly during peak hours, where the index can soar to 11 around noon. By staying informed about the daily UV Index, you can enjoy the sunny Colorado outdoors while keeping your skin safe and healthy.
The UV Index for today shows a dramatic rise as the sun ascends into the sky. Starting at a mild 1 by 07:00, the index gradually builds, reaching 3 by 09:00 and peaking at an intense 11 at 13:00—a level where sun protection is crucial. From this pinnacle, the values start to decline, tapering off to 10 at 14:00 and then gradually decreasing through the afternoon and evening, with values of 6 at 16:00 and sliding down to 1 by 19:00. Plan your outdoor activities accordingly, and remember to protect your skin 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 | 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 too does the UV Index, which significantly impacts sun exposure risks. January kicks off with a moderate UV Index of 4, allowing for 30 minutes of safe sun exposure. However, by February, the index rises to 6 (high), reducing burn time to 25 minutes. The months of March to August see a sharp increase, peaking at an extreme level of 11 in both June and July, where only 10 minutes of exposure can lead to burns. April and May also remain perilously high with indices of 9 and 10, respectively. As fall approaches, the UV Index begins to decrease slowly, but September to October still pose a risk with very high readings of 9 and 8. The year's end brings moderate levels again in November and December, with UV Indices of 5 and 3, respectively. It's crucial for residents and visitors to stay informed and protect themselves, especially during the high-risk months from March to August, where proper sun protection, such as sunscreen and protective clothing, is strongly advised.
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 |
| Littleton | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 9 | 8 | 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 |