Last updated: August 1, 2025
Understanding the UV Index is essential for residents and visitors in Alegrete, Portugal, where the Mediterranean climate brings warm, sunny days that can increase exposure to harmful ultraviolet rays. With a high UV Index peaking at 10 during midday, awareness of these levels is crucial for preventing sunburn and protecting long-term skin health. Knowing when the UV levels are at their highest helps you take proactive measures, ensuring that outdoor activities remain enjoyable and safe. As Alegrete basks in its sunny climate, keeping an eye on the UV Index can make all the difference in maintaining your well-being while exploring this beautiful region.
The UV Index chart reveals a dynamic daily pattern of solar intensity. Starting early in the day, the UV Index remains low, peaking at 1 by 08:00. However, as the sun reaches its zenith, the index surges dramatically—hitting 7 by 11:00 and soaring to a maximum of 10 between 13:00 and 14:00. This signals a critical window for sun exposure, where protection is essential. As the afternoon progresses, the UV levels begin to decline, dropping to 4 by 17:00, before tapering off to 1 again by evening. To stay safe, it's vital to be cautious during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 10 | 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 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, so do UV radiation levels, significantly impacting sun safety for residents and visitors. From January to February, the UV Index remains at a moderate level (3-4), with a burn time of 30 minutes. In March, the index rises to 6, classifying it as high, with a reduced burn time of 25 minutes. The real risk begins in April, when the UV Index skyrockets to 9 (very high), with a burn time of just 15 minutes. The peak arrives during June, where the Index reaches 11, categorized as extreme, leading to a minimal burn time of 10 minutes. This elevated risk continues through July and August, before tapering off in September to a still significant 8, and returning to high levels of 6 in October. As UV levels decline in November and December, with indices dropping back to moderate (3-4), residents and visitors should take special care from April to September, practicing sun safety measures, including using sunscreen, wearing protective clothing, and seeking shade during peak hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Braga UVI | 2 | 4 | 6 | 8 | 9 | 11 | 10 | 9 | 8 | 6 | 4 | 2 |
| Porto UVI | 2 | 4 | 6 | 8 | 9 | 11 | 10 | 9 | 8 | 6 | 4 | 2 |
| Amadora UVI | 3 | 5 | 6 | 9 | 10 | 11 | 10 | 9 | 8 | 6 | 4 | 3 |
| Lisbon UVI | 3 | 5 | 6 | 9 | 10 | 11 | 10 | 9 | 8 | 6 | 4 | 3 |
| Setubal UVI | 3 | 5 | 6 | 9 | 10 | 11 | 10 | 9 | 8 | 6 | 4 | 3 |
| Alegrete | 3 | 4 | 6 | 9 | 10 | 11 | 10 | 10 | 8 | 6 | 4 | 3 |