Last updated: May 3, 2025
In Alter do Chao, Portugal, staying aware of the UV Index is crucial for protecting your skin against harmful sun exposure. Understanding UV levels not only helps in preventing sunburn but also plays a vital role in promoting long-term skin health. With a Mediterranean climate and peak UV Index values reaching as high as 10 during the midday hours, residents and visitors must be vigilant about their sun safety practices. Whether lounging by the beach or exploring the beautiful surroundings, keeping an eye on UV levels is key to enjoying the sun responsibly in this stunning region.
As the sun rises, the UV Index begins its gentle ascent, starting at 1 at 07:00. By 09:00, it climbs to 3, hinting at the day's potential for sun exposure. The heat peaks around 12:00, reaching a blistering 9, and hits its maximum at 13:00 and 14:00, both at a high of 10—a critical time for sun safety. As the afternoon transitions to evening, the UV Index gradually dips; by 18:00, it's down to 2, and as twilight approaches, it settles back at 1 by 19:00. Plan your outdoor activities wisely to stay safe in the sun!
| 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 | 10 | very high | 15 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 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 |
| Alter do Chao | 3 | 4 | 6 | 9 | 10 | 11 | 10 | 10 | 8 | 6 | 4 | 3 |