Last updated: June 2, 2025
Understanding the UV Index is essential for residents of Rosario do Sul, Brazil, where the subtropical Cfa climate leads to considerable sun exposure throughout the year. Being aware of the UV levels helps residents take proactive measures against sunburn and long-term skin damage, ensuring overall skin health. Typically, UV levels peak around midday, reaching a maximum of 4 between 11 AM and 2 PM, indicating a moderate risk of harm from unprotected sun exposure. By keeping an eye on the UV Index, you can enjoy the sunny days while protecting your skin from potential hazards.
The UV Index throughout the day clearly illustrates its early morning calm before reaching the peak around midday. Starting at a maximum of 0 at 07:00, the index gradually rises to 1 by 08:00 and remains slight until it hits 2 at 10:00. The real intensity is felt between 11:00 and 13:00, where it peaks at 4, emphasizing the importance of sun protection during these hours. As the afternoon unfolds, the index steadily declines, dropping back to 2 by 15:00 before tapering off to 1 at 16:00 and returning to 0 by 18:00. Overall, this data underscores the significant variation of UV exposure throughout the day, encouraging us to be mindful of sun safety during its highest points.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 0 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 1 | low | 45 min |
| 10:00 | 2 | low | 45 min |
| 11:00 | 4 | moderate | 30 min |
| 12:00 | 4 | moderate | 30 min |
| 13:00 | 4 | 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 |
Throughout the year, UV exposure varies significantly, with the highest risk occurring in January, February, and March, all showing an extreme UV Index of 15 to 12, and a burn time of just 10 minutes. As we transition into the warmer months, April and September display a very high UV Index of 9, necessitating caution with a burn time of 15 minutes. The summer months of June and July offer a moderate level of UV exposure, allowing for a slightly extended burn time of 30 minutes. Notably, August shifts back to a high category with a UV Index of 7. As winter returns in October through December, UV levels rise back to extreme, emphasizing the need for protection with a burn time of 10 minutes. Visitors and residents are strongly advised to remain vigilant during high-risk months—especially from January to March and October to November—by wearing sunscreen, protective clothing, and seeking shade when the UV index is elevated.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rosario do Sul | 15 | 14 | 12 | 9 | 6 | 4 | 5 | 7 | 9 | 12 | 14 | 15 |
| 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 |
| Fortaleza UVI | 14 | 14 | 15 | 15 | 13 | 11 | 11 | 12 | 13 | 13 | 13 | 13 |