Last updated: July 2, 2025
Awareness of the UV Index is crucial for residents of Bristol, United States, a region that experiences a humid subtropical climate (Cfa) with varying levels of sun exposure throughout the year. Understanding UV levels is vital not just for avoiding painful sunburns, but also for protecting your skin’s long-term health. With peak UV Index readings soaring to 11 during midday hours, it’s essential for locals to stay informed about daily UV risks. By monitoring these levels, you can take proactive measures to enjoy the sun safely while minimizing the risk of skin damage.
The UV Index throughout the day presents an intriguing pattern of increasing intensity. Starting from a low of 1 at 07:00, the index creeps up slowly until it reaches 3 by 09:00. As the sun climbs higher, there's a notable surge, peaking at 11 from 13:00 to 14:00, indicating a high level of UV exposure. After 15:00, the numbers begin to taper off, descending to 5 by 17:00 and dwindling to 1 by 19:00. This data underscores the importance of sun protection during the midday hours when the UV Index is at its highest — reaching an impressive 9 and 11 during the critical midday 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 | 7 | high | 25 min |
| 12:00 | 9 | 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 | 5 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index experiences a significant increase from winter to summer, peaking during the high-risk months of May, June, and July, where it reaches an extreme level of 11 and a burn time of just 10 minutes. As we transition into spring, March and April also show very high levels (UV Index 8 and 10, respectively), resulting in a burn time of 15 minutes. Visitors and residents should be particularly cautious during these months, seeking shade, wearing protective clothing, and applying sunscreen frequently, as exposure can lead to skin damage in a matter of minutes. From August to October, the index gradually decreases; however, September and October still present high risks (UV Index 10 and 8) with a burn time of 15 minutes. As winter arrives, UV levels dip to moderate, and the burn times increase to 30 minutes in November and December, suggesting a lower risk of UV exposure. Always prioritize sun safety, especially in the warmer months.
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 |
| Bristol | 4 | 6 | 8 | 10 | 11 | 11 | 11 | 10 | 10 | 8 | 5 | 3 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |