Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors of São Sebastião do Caí, Brazil, where sunlight is plentiful throughout the year. The UV Index provides vital information about the strength of UV radiation on a given day, which is essential for preventing sunburn and maintaining long-term skin health. With a Cfa climate typical of this region, individuals face varying levels of UV exposure, particularly during peak hours where the index can reach as high as 5 between noon and 1 PM. Staying informed about these levels helps you enjoy the beautiful Brazilian sunshine while protecting your skin from harmful rays.
As the sun rises, the UV Index begins at 0 at 7:00 AM, offering a safe start to the day. By 8:00 AM, it climbs to 1, indicating minimal risk for most people. As the morning progresses, the UV Index reaches 3 by 10:00 AM, signaling a moderate level that advises some sun protection if you're outdoors. The peak intensity occurs at 12:00 PM with a reading of 5, which translates to a higher risk of harm from unprotected sun exposure. Fortunately, the UV levels gradually decrease throughout the afternoon, dropping to 3 at 2:00 PM and further down to 1 by 4:00 PM. As evening falls, the index diminishes to 0 by 6:00 PM, bringing relief from the sun's rays. Overall, it’s a day to enjoy the sun safely, with peak caution needed during the midday hours.
| 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 | 3 | moderate | 30 min |
| 11:00 | 4 | moderate | 30 min |
| 12:00 | 5 | moderate | 30 min |
| 13:00 | 4 | moderate | 30 min |
| 14:00 | 3 | 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 exhibit significant seasonal fluctuations, with particularly high-risk months from January to March and October to December, where the UV Index reaches extreme levels (13-14) and burn times are as short as 10 minutes. The month of April sees a decline to a very high category (UV Index 9) with a burn time of 15 minutes, while May and August present high risk (UV Index 6-7) but with longer burn times of 25 minutes. From June to July, the UV Index reduces to moderate levels (5), allowing for safer sun exposure of 30 minutes. Visitors and residents are strongly advised to take precautions during the extreme and very high risk months, including wearing sunscreen, seeking shade, and wearing protective clothing to minimize the risk of sunburn and long-term skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sao Sebastiao do Cai | 14 | 13 | 12 | 9 | 6 | 5 | 5 | 7 | 9 | 12 | 13 | 14 |
| 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 |