Last updated: July 2, 2025
Understanding the UV Index is essential for residents and visitors in Nobres, Brazil, where the tropical Aw climate often leads to high sun exposure. Being aware of UV levels can significantly contribute to sunburn prevention and overall skin health, reducing the risk of long-term damage. With peak UV Index values reaching 9 around midday, it's crucial to safeguard your skin from harmful rays during the sunniest hours. In Nobres, where outdoor activities abound, staying informed about daily UV exposure risks will help you enjoy the natural beauty without compromising your health.
The UV Index throughout the day demonstrates a distinct peak during the midday hours, reaching its maximum of 9 at 11:00 AM and again at 12:00 PM. As the sun rises, the UV Index begins at a mere 1 at 7:00 AM, gradually climbing to 4 by 9:00 AM. However, once the clock strikes 10:00 AM, the intensity escalates sharply to 7 before hitting its zenith. Following this, there is a slight tapering off in the afternoon hours, with values nearing 6 at 2:00 PM and gradually decreasing to 3 by 3:00 PM. As daylight wanes, the UV Index plummets, dropping to 1 by 4:00 PM and finally settling at 0 by 6:00 PM, signaling an end to the sun's powerful rays for the day. This data emphasizes the importance of sun protection, especially during those peak hours between 10:00 AM and 2:00 PM.
| 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 | 9 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 6 | high | 25 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 displays significant seasonal variations, with extreme levels dominating from January through April, where the UV Index remains consistently high at 16 or 15, resulting in a burn time of just 10 minutes. The risk diminishes slightly in May and June, dropping to 10 and 9, but still remains in the very high category, allowing for a burn time of 15 minutes. August sees a resurgence in risk with an index of 11, while September to November maintains an extreme category, with values fluctuating between 12 and 15 and a short burn time of 10 minutes. December returns to a UV Index of 16, signaling harsh conditions again. Visitors and residents should take precautions during these high-risk months, particularly between January and April, and when the index rises above 10, by wearing protective clothing, applying sunscreen, and limiting sun exposure to prevent harmful effects.
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 |
| Nobres | 16 | 16 | 15 | 13 | 10 | 9 | 9 | 11 | 12 | 14 | 15 | 16 |
| Fortaleza UVI | 14 | 14 | 15 | 15 | 13 | 11 | 11 | 12 | 13 | 13 | 13 | 13 |