Last updated: June 2, 2025
In Sao Joao de Meriti, Brazil, being aware of the UV Index is crucial for maintaining skin health and preventing sunburn, especially in a region characterized by its tropical climate. Understanding the daily fluctuations in UV levels can help residents and visitors enjoy the sun safely, minimizing the risk of skin damage and other associated health concerns. Typically, the UV Index peaks between 11:00 AM and 1:00 PM with values reaching 6, indicating a high risk of harm from unprotected sun exposure. By staying informed about these levels, you can enjoy the beautiful outdoors while protecting your skin from the intense sunlight that comes with the region's warm conditions.
The UV Index starts low in the early morning, with a maximum of 1 at 07:00 and 08:00, making it a safe time for outdoor activities. As the day progresses, the intensity rises sharply, peaking at 6 between 11:00 and 12:00—the perfect time to take precautions if heading outside. By 13:00, it dips slightly to 5, and a more noticeable decline occurs in the afternoon, falling to 2 by 15:00. As the sun sets, the UV Index drops off sharply, reaching 1 by 16:00, and finally 0 past 18:00. It’s clear that midday sun calls for some sun safety measures, but the later hours provide a much more forgiving environment for enjoying the outdoors!
| 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 | 4 | 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 |
Throughout the year, UV Index values experience significant fluctuations, with January, February, March, September, October, November, and December categorized as high-risk months due to their extreme exposure levels (UV Index 13-15) and a rapid burn time of 10 minutes. In contrast, April and August will see very high readings (UV Index 10 and 9, respectively) with a burn time of 15 minutes, while May, June, and July present a high exposure risk (UV Index 6-7) but with extended burn times of 25 minutes. To protect themselves, visitors and residents should strictly limit sun exposure during these high-risk months, seek shade whenever possible, and apply broad-spectrum sunscreen regularly, especially during peak sun hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sao Joao de Meriti | 15 | 14 | 13 | 10 | 7 | 6 | 7 | 9 | 11 | 12 | 13 | 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 |