Last updated: August 1, 2025
Staying informed about the UV Index is essential for residents and visitors of Serra Negra, Brazil, where the lush landscapes are often accompanied by strong sun exposure. Understanding UV levels is crucial for effective sunburn prevention and protecting your skin health, especially when the index can reach as high as 8 during midday hours. With Serra Negra's Cfa climate, characterized by warm summers and mild winters, awareness of UV risks becomes even more pertinent, as outdoor activities may lead to increased sun exposure. Remember, just a few minutes in peak sunlight can lead to serious skin damage—stay informed and protected!
The UV Index throughout the day presents a clear pattern, peaking around noon with a maximum value of 8, indicating that sun protection is crucial during this time. Starting from a low of 1 at 07:00 and 08:00, the index rises steadily, hitting 5 by 10:00. It escalates to its highest point at 12:00, before gradually declining to 7 at 13:00 and then dropping further as the afternoon progresses. By 16:00, the index has decreased to 2, and finally, it settles to 0 by 18:00, meaning minimal risk of harm from sun exposure as daylight fades. For outdoor enthusiasts, the best advice is to stay safe and protect against UV rays, especially around midday!
| 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 | 9 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 4 | moderate | 30 min |
| 16:00 | 2 | 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 variation, peaking during the winter and early spring months. From January to April, the UV Index remains in the extreme exposure category, with a consistent reading of 16. This is particularly important for visitors and residents, as the burn time is just 10 minutes. As we transition into warmer months, May through August presents very high UV levels, with indices dropping slightly but remaining impactful, especially in July and August. The burn time extends to 15 minutes during these months. September to November sees a return to extreme levels, with UV Index values between 12 and 16, and a burn time of 10 minutes. To protect your skin, all individuals should prioritize sun safety measures—such as using sunscreen, wearing protective clothing, and limiting sun exposure during peak hours—throughout the year, but especially during the high-risk months from January to April and again in September to November.
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 |
| Serra Negra | 16 | 16 | 13 | 11 | 8 | 6 | 8 | 10 | 12 | 14 | 15 | 16 |
| 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 |