Last updated: July 2, 2025
Understanding the UV Index is essential for residents and visitors of Lisbon, United States, where the sun can be a significant factor in daily life. With peak UV levels often soaring to 9 during the midday hours, being aware of these fluctuations is critical for preventing sunburn and protecting skin health. The Dfb climate in Lisbon brings warm summers and cold winters, but the risk of UV exposure remains high, particularly between 11 AM and 3 PM. Staying informed about the UV Index allows you to enjoy the outdoors while taking necessary precautions for your skin's well-being.
As the sun rises, the UV Index gradually climbs, starting at a low of 1 by 07:00 and 08:00. The real leap begins at 09:00, where it reaches 3, escalating to 4 by 10:00. As noon approaches, the UV Index peaks at an impressive 9 from 13:00 to 14:00, making it crucial to take protective measures during those hours. Afterward, it begins to taper off, dropping to 6 by 16:00, and further declining through the late afternoon and evening, eventually falling back to 1 by 19:00. For those venturing outdoors, staying vigilant to the UV levels during the midday hours is essential for skin protection!
| 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 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | 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 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, the UV Index experiences notable fluctuations, influencing both visitor and resident safety. January and December boast a low UV Index of 2, allowing for extended exposure times of 45 minutes without significant risk. However, as we move into spring with February and March, the UV Index rises to 4 and 5 respectively, indicating a moderate risk with a burn time of just 30 minutes. The high-risk months arrive in April through August, with peak values of 9 and 10 during May and June, categorizing the exposure as very high and shortening safe sun exposure to as little as 15 minutes. September sees a slight decrease to a high index of 7, while October and November return to moderate levels. Visitors and residents should take precautionary measures during the higher UV months by seeking shade, wearing protective clothing, and using sunscreen regularly to minimize skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lisbon | 2 | 4 | 5 | 7 | 9 | 10 | 9 | 8 | 7 | 5 | 3 | 2 |
| 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 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |