Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Riachos, Portugal, where sunny days are a hallmark of the local climate. Being aware of UV levels not only helps in preventing painful sunburns but also plays a significant role in maintaining overall skin health. With peak UV readings reaching a whopping 10 around midday, it's essential to stay informed about daily exposure risks in this region. Riachos, nestled in a Csa climate zone, experiences ample sunshine, making UV protection a key component of outdoor activities—particularly during the intense midday hours when UV rays pose the highest risk. Stay safe and enjoy the sun wisely!
The UV Index for the day showcases a striking ascent in intensity, peaking during the afternoon hours. Starting from a low of 1 at 07:00 and 08:00, the index swiftly climbs to reach 3 by 09:00. By 10:00, it escalates to a moderate 5, but the real surge occurs between 11:00 and 14:00, hitting a maximum of 10—indicating a high risk of harm from unprotected sun exposure. As the day progresses, the UV Index gradually drops, retracting to 4 by 17:00 and further declining to 1 by 19:00. It's crucial to stay protected during those peak hours!
| 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 | 9 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index shows significant seasonal variations, with high-risk months identified from March through September. In this period, the UV Index reaches its peak in June at 11 (extreme), demanding vigilance due to a burn time of just 10 minutes. Visitors and residents should take precautions, especially in April, May, June, and July, when the UV levels are categorized as very high and the recommended burn time is reduced to 15 minutes. It is advisable to wear sunscreen, seek shade, and don protective clothing during these months to minimize skin damage. Conversely, during the months of January, November, and December, the UV Index is categorized as moderate, allowing for more extended sun exposure of around 30 minutes without immediate risk. However, caution should still be exercised throughout the year.
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 |
| Riachos | 3 | 4 | 6 | 8 | 10 | 11 | 10 | 9 | 8 | 6 | 4 | 3 |
| 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 |