Last updated: June 2, 2025
Understanding the UV Index is vital for residents and visitors of Rio Claro, Brazil, where the subtropical climate leads to significant sun exposure. Being aware of UV levels not only helps in preventing painful sunburn but also plays a crucial role in maintaining long-term skin health. As Rio Claro enjoys sunny days, particularly from late morning to early afternoon when UV Index values peak at a moderate level of 6, it's essential to take precautions during these hours to safeguard yourself against harmful ultraviolet rays. By staying informed about the UV Index, you can enjoy the beautiful weather while protecting your skin!
As the day unfolds, the UV Index begins to rise, peaking sharply around midday. From a gentle 1 at 7 AM, it escalates to a moderate 6 between 11 AM and 1 PM, signaling peak sun exposure. During these crucial hours, it's essential to protect your skin with sunscreen and wear appropriate clothing. As the afternoon progresses, the intensity wanes, dropping to 4 at 2 PM and further declining to 3 by 3 PM. By 4 PM, it returns to a safe 1, and finally settles to 0 after sunset, making late afternoon and evening hours ideal for outdoor activities without the risk of UV damage. Stay informed and enjoy the sun responsibly!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 6 | high | 25 min |
| 13:00 | 6 | high | 25 min |
| 14:00 | 4 | moderate | 30 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 |
Throughout the year, the UV Index shows significant seasonal changes, with high-risk months primarily falling between January and April, where the UV Index remains at an extreme level of 16 to 11 and the burn time is limited to just 10 minutes. This level of risk returns in September through November, where the index spikes again to numbers as high as 14 for November. May introduces a decrease to a very high category with an index of 8, followed by June and July, which stabilize at a high level with an increased burn time of 25 minutes. By August, there's a resurgence to very high, so caution is advised. Therefore, visitors and residents should prioritize sun safety by seeking shade, wearing protective clothing, and applying sunscreen, especially during the months of January to April and September to November when the risk of UV exposure is greatest.
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 |
| Rio Claro | 16 | 16 | 13 | 11 | 8 | 6 | 7 | 10 | 12 | 13 | 14 | 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 |