Last updated: May 3, 2025
Understanding the UV Index in Sao Joao do Piaui is crucial for maintaining your skin health and preventing sunburn, especially in a region marked by a BSh climate that often exposes residents and visitors to high levels of ultraviolet radiation. With peak UV levels soaring to 12 around noon, awareness of these figures helps you make informed choices about sun protection and outdoor activities. As the sun climbs high from morning until late afternoon, knowing the UV exposure risks can safeguard you against harmful effects, ensuring that your time under the Brazilian sun is both enjoyable and safe.
The UV Index throughout the day exhibits a dramatic rise as the sun reaches its apex. Starting at a minimal 1 at 07:00, the index climbs gradually, hitting 3 by 08:00. The real heat arrives at 09:00, when it surges to 6, peaking at a striking 12 from 11:00 to 12:00—an indication to seek shade and protect your skin. As the afternoon progresses, the index begins to descend, dropping to 10 at 13:00, then gradually decreasing to 4 by 15:00. By late afternoon, the UV intensity diminishes, with values falling to 2 at 16:00, and becoming negligible, hitting 1 by 17:00 before fading into the night with a 0 at 18:00 and beyond. Stay informed and shield yourself from those midday rays!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 12 | extreme | 10 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 10 | 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 remains consistently high throughout the year, with extreme exposure categories dominating every month. Notably, January to March see a peak UV Index of 15, marking these months as high-risk for skin damage, where a mere 10 minutes of unprotected sun exposure can lead to burns. The UV levels gradually decrease from April to June, dropping to 11, but still maintaining an extreme level of risk. Even later months into August and September, the UV Index remains significant, reaching 12 and 13, respectively. With high UV levels persisting into October and November (both at 14), it’s crucial for visitors and residents to take proactive measures, including wearing sunscreen, hats, and UV-protective clothing, especially during the midday hours, to mitigate the risks associated with prolonged sun exposure.
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 |
| Fortaleza UVI | 14 | 14 | 15 | 15 | 13 | 11 | 11 | 12 | 13 | 13 | 13 | 13 |
| Sao Joao do Piaui | 15 | 15 | 15 | 14 | 12 | 11 | 11 | 12 | 13 | 14 | 14 | 14 |