Last updated: June 2, 2025
In Littleton, United States, being aware of the UV Index is crucial for protecting your skin and overall health. Understanding UV levels helps you take proactive measures to prevent sunburn and long-term skin damage, making it essential for outdoor enthusiasts and casual sunbathers alike. With a Cfa climate, Littleton experiences varying UV exposure, peaking around midday with indices reaching as high as 11—a level that indicates a very high risk of harm from unprotected sun exposure. Stay informed and enjoy the sunshine safely!
As the sun rises, the UV Index starts off gently at 1 by 7:00 AM, gradually climbing as the day progresses. By 10:00 AM, it reaches 6, signaling a notable increase in solar radiation. The intensity peaks at 12:00 PM with a striking 10 and continues to soar to a maximum of 11 at 1:00 PM, marking the hour of greatest exposure. As the afternoon unfolds, the index begins to taper off—dropping to 10 at 2:00 PM and 8 by 3:00 PM. By late afternoon, the UV Index gracefully descends to 4 at 5:00 PM, settling back to 2 by 6:00 PM and finally returning to a gentle 1 by 7:00 PM. This highlights the importance of sun protection during mid-day when UV rays are at their most intense.
| 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 | 8 | 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 |