Last updated: June 2, 2025
Being aware of the UV Index is crucial for residents and visitors in Porteirinha, Brazil, where the warm Aw climate brings a heightened risk of sun exposure. Understanding the UV levels throughout the day is vital for preventing sunburn and safeguarding skin health. During typical hours, particularly between 10 AM and 2 PM, the UV Index can peak dramatically, reaching levels as high as 9—indicating a strong risk of harm from unprotected sun exposure. By staying informed, you can enjoy the beautiful Brazilian sun while minimizing the risks to your skin.
At 07:00, the UV Index begins its ascent at a mild level of 1. By 08:00, it rises to 2, providing a gentle reminder of the sun's presence. A noticeable leap occurs at 09:00, reaching 4 as outdoor activities start to pick up. The intensity peaks sharply at 11:00, where it hits 8, marking the midday sun's strength. The highest point is at 12:00, with a staggering 9, urging caution for sun-sensitive individuals. As the afternoon progresses, the index gradually declines to 5 by 14:00 and further to 3 at 15:00. By 16:00, it falls to 1, and by 18:00, the UV Index drops to 0, signaling a safe return outdoors as the sun sets, followed by a complete absence of UV radiation by 19:00. Enjoy the sunshine, but remember—protection is key during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 7 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 5 | moderate | 30 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 exhibits significant seasonal variations, with the highest readings occurring during the winter and late fall months. **From January to April, the UV Index remains consistently extreme, peaking at 16 in December and dropping slightly to 13 in April. The risk is particularly acute in February (UV Index 15) and November (UV Index 15), necessitating vigilant sun protection. As summer arrives, the index slightly declines, with June and July recording a very high index of 9 and 10, respectively, allowing for a longer burn time of 15 minutes. However, as fall sets in, August and September return to extreme levels (12), before transitioning back to winter’s extremes. Visitors and residents should take precautions during high-risk months by applying broad-spectrum sunscreen, wearing protective clothing, and seeking shade, especially during peak sun hours. Given the consistently high UV levels year-round, staying aware and prepared is essential for skin safety.
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 |
| Porteirinha | 15 | 15 | 14 | 13 | 11 | 9 | 10 | 12 | 12 | 14 | 15 | 16 |
| Fortaleza UVI | 14 | 14 | 15 | 15 | 13 | 11 | 11 | 12 | 13 | 13 | 13 | 13 |