Last updated: June 2, 2025
In Barra do Piraí, Brazil, being aware of the UV Index is crucial for safeguarding your skin health under the tropical sun. With a typical Cfa climate characterized by warm summers and moderate UV exposure, understanding the daily UV levels—which can peak at 6 during midday—is essential for effective sunburn prevention. By monitoring these UV levels, you can take proactive steps to protect yourself, ensuring that your outdoor activities are enjoyable and safe from harmful radiation. Remember, even during hours with lower indices, applying sunscreen and wearing protective clothing can make all the difference in your skin's long-term health.
The UV Index throughout the day presents a dynamic picture of sun exposure. Early hours from 07:00 to 08:00 are marked by a low index of 1, making sun protection minimal. However, as the day unfolds, the intensity rises sharply; by 09:00, it reaches 3, climbing to a peak of 6 at both 11:00 and 12:00. During this time, it's crucial to take precautions against harmful rays. As the afternoon progresses, the UV Index gradually declines, dropping to 5 at 13:00 and further to 4 by 14:00. By late afternoon, the levels fall to 2 at 15:00 and drop to 1 by 16:00, and the sun's strength wanes completely after 18:00, where it dips to 0. Plan your outdoor activities wisely!
| 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 | 6 | high | 25 min |
| 12:00 | 6 | high | 25 min |
| 13:00 | 5 | moderate | 30 min |
| 14:00 | 4 | moderate | 30 min |
| 15:00 | 2 | low | 45 min |
| 16:00 | 1 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 0 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The seasonal UV changes demonstrate that UV exposure remains particularly high during the first half of the year, with extreme levels peaking from January to April, where a burn can occur in as little as 10 minutes of unprotected sun exposure. High-risk months include January through April and September through November, all classified under the extreme exposure category, signaling the need for heightened sun safety measures during these times. As the year progresses into May, the UV Index drops to very high before transitioning to high levels in June and July, allowing for slightly longer burn times of 15 to 25 minutes. Visitors and residents are advised to take precautions year-round, but especially during the extreme months, by wearing sunscreen, protective clothing, and seeking shade to mitigate the risk of UV-related health issues.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rio de Janeiro UVI | 15 | 14 | 13 | 10 | 7 | 6 | 7 | 9 | 11 | 12 | 13 | 15 |
| Sao Paulo UVI | 16 | 15 | 12 | 11 | 8 | 6 | 7 | 9 | 11 | 13 | 14 | 15 |
| Barra do Pirai | 16 | 15 | 13 | 11 | 8 | 6 | 7 | 9 | 11 | 13 | 13 | 15 |
| Belo Horizonte UVI | 17 | 16 | 14 | 12 | 9 | 7 | 8 | 10 | 12 | 13 | 14 | 16 |
| Salvador UVI | 14 | 14 | 14 | 13 | 10 | 9 | 9 | 12 | 12 | 15 | 15 | 14 |
| Fortaleza UVI | 14 | 14 | 15 | 15 | 13 | 11 | 11 | 12 | 13 | 13 | 13 | 13 |