Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in Castro Alves, Brazil, where the sun shines brightly in a tropical climate. With UV levels peaking at an intense 11 around midday, awareness of these fluctuations is essential for protecting your skin from harmful ultraviolet radiation and preventing painful sunburns. By being informed about the UV Index, you can make safer outdoor choices, ensuring your skin health remains a priority. The combination of Castro Alves' warm temperatures and elevated UV exposure makes it vital to stay vigilant and take appropriate sun safety measures throughout the day.
As the sun rises, the UV Index climbs steadily, starting at a gentle 1 at 7:00 AM. By 8:00 AM, it reaches 3, marking the beginning of increased sun exposure. The day continues to heat up, with the index peaking at a remarkable 11 from 11:00 AM to 12:00 PM, indicating a high risk for harm from unprotected sun exposure. As the afternoon sets in, it gradually declines, dropping to 6 by 2:00 PM and subsequently to 3 by 3:00 PM. As the sun begins to descend, the index returns to a safer 1 by 4:00 PM and tapers off to 0 after 6:00 PM. This hourly trend underscores the importance of sun protection during the midday hours when the UV exposure is at its highest.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 6 | high | 25 min |
| 15:00 | 3 | moderate | 30 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 UV Index showcases significant seasonal changes, with extreme exposure levels predominating from January to April and again from August to November. The highest-risk months include January, February, March, and April, where the UV Index consistently reaches 14 to 15, resulting in a burn time of just 10 minutes. Notably, June and July present slightly lower but still concerning levels of very high exposure with a UV Index of 9 to 10 and a burn time of 15 minutes. As visitors and residents navigate these months, it is imperative to take precautions, such as wearing sunscreen, protective clothing, and seeking shade, especially during peak sunlight hours. Prioritizing sun safety is essential year-round, but particularly so during these high UV periods.
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 |
| 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 |
| Castro Alves | 15 | 14 | 14 | 13 | 11 | 9 | 10 | 12 | 13 | 15 | 15 | 14 |
| Fortaleza UVI | 14 | 14 | 15 | 15 | 13 | 11 | 11 | 12 | 13 | 13 | 13 | 13 |