Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors of Barao de Sao Joao, Portugal, as it plays a significant role in protecting skin health and preventing sunburn. With the region's Csa climate, typical UV levels can spike dramatically, especially between 11 AM and 2 PM, where indices soar to 11, indicating extreme exposure risk. By staying informed about daily UV levels, you can take proactive measures to safeguard your skin while enjoying the beautiful outdoors of this picturesque area. Embrace the sun responsibly and keep your skin healthy!
As the sun rises, the UV Index begins at a gentle 1 at 07:00 and 08:00, indicating minimal sun exposure risk. However, by 09:00, it jumps to 3 and continues to climb rapidly, reaching a significant 8 by 11:00. High noon brings the peak UV index of 10 at 12:00, followed by an intense 11 from 13:00 to 14:00, signaling a critical time for sun protection. As the afternoon wanes, the index starts to decline, dropping to 9 at 15:00, then decreasing to 7 at 16:00 and 5 by 17:00. Post-sunset, the index falls sharply to 3 at 18:00 and settles back at 1 as the day concludes at 19:00. This data underscores the importance of staying shielded from midday sun when the UV radiation is at its strongest.
| 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 | 8 | very high | 15 min |
| 12:00 | 10 | 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 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Seasonal changes in UV radiation show a significant increase from late winter through summer, peaking during the hotter months. High-risk months with extreme UV levels include June (UV Index 11) and July to August (UV Index 10), where the burn time is as little as 10 to 15 minutes. Visitors and residents should take precautionary measures during these months, such as wearing protective clothing, using broad-spectrum sunscreen, and minimizing sun exposure between 10 AM and 4 PM. As fall approaches, UV levels gradually decrease, but it remains important to stay aware, particularly in March through October, when the UV index often enters the high to very high categories.
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 |
| Barao de Sao Joao | 3 | 5 | 6 | 9 | 10 | 11 | 10 | 10 | 9 | 7 | 4 | 3 |