Last updated: August 1, 2025
Understanding the UV Index is crucial for residents of Jau, Brazil, where the warm Aw climate leads to significant sun exposure. With UV levels reaching their peak at 7 between noon and 1 PM, being aware of these fluctuations is essential to prevent sunburn and promote long-term skin health. Daily outdoor activities can expose you to harmful rays, making it important to monitor those UV levels, especially during the sunniest hours. Stay informed, stay safe, and enjoy the beautiful Brazilian sun while protecting your skin from its risks!
The UV Index exhibits a dynamic pattern throughout the day, peaking sharply around midday. Starting off mild at 07:00 and 08:00 with a UV Index of 1, exposure remains minimal. However, as the sun climbs, the intensity increases significantly by 09:00, reaching 3, and continues to rise to a notable peak of 7 at 12:00 and 13:00. This indicates a need for sun protection during these hours. By 14:00, the UV Index begins to decline, falling to 5, and subsequently drops further, settling at 1 by 17:00 and finally reaching 0 by 18:00. In summary, the day's UV exposure highlights the importance of vigilance against UV radiation, particularly between 10:00 and 14:00 when the sun’s rays are at their strongest.
| 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 | 6 | 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 experiences significant seasonal fluctuations, peaking during the first and last months of the year. From January to April, the index ranges from 15 to 11, categorized as extreme exposure, with a brief burn time of just 10 minutes. May marks a slight decrease to 8, categorized as very high. By June and July, the index stabilizes at 7, indicating high exposure, allowing for a longer burn time of 25 minutes. The summer months transition back to higher risks in August (UV Index 10) and then spike again from September to December, where values rise to 16 in December, also categorized as extreme. Visitors and residents should take necessary precautions, especially during high-risk months: January, February, March, April, September, October, November, and December, as exposure can lead to severe sunburn in as little as 10 minutes. It's crucial to wear protective clothing, apply sunscreen, and seek shade, particularly during peak hours.
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 |
| Jau | 15 | 16 | 13 | 11 | 8 | 7 | 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 |