Last updated: August 1, 2025
In Caieiras, Brazil, being aware of the UV Index is crucial for maintaining your skin health and preventing sunburn. Understanding UV levels empowers residents and visitors alike to take necessary precautions against harmful radiation, particularly during midday when the index peaks at 7. This city, with its Cfa climate, experiences varied UV exposure risks, especially in the warmer months. With such fluctuating UV levels throughout the day, staying informed can help you enjoy the sun safely.
At dawn, the UV Index starts off low, with a maximum of 1 at 07:00 and 08:00. As the sun rises higher, it reaches 3 by 09:00, before climbing to a peak of 7 at 12:00. This midday intensity signifies a need for sun protection, especially during the height of the day when UV exposure is most potent. The index begins to decline in the afternoon, dropping to 5 at 14:00 and settling back to 1 by 17:00. By 18:00 and into the evening, the UV Index sharply drops to 0, marking a safe time to enjoy outdoor activities without the risk of sunburn. Stay sun-safe!
| 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 | 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 fluctuations, with the highest levels consistently occurring in the winter months of January and February, where both register at 16, categorizing exposure as extreme and necessitating a mere 10 minutes of sun exposure before burning. Following closely, March through April also showcases extreme UV levels, before tapering slightly in May, where the index drops to 8 but remains in the very high range. June and July see mild reductions, landing at 6 and 7, respectively, representing high exposure risks with a burn time of 25 minutes. Nevertheless, as the season transitions back to fall, September and October return to extreme levels, particularly notable in September at 11 and October at 13, while November maintains a high index of 14. Visitors and residents should remain vigilant from January through April and again in September and October, as these are critical months for high UV exposure risks. It's advisable for everyone to adopt protective measures, including wearing sunscreen and protective clothing, during these high-risk periods to minimize adverse effects from UV 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 |
| Caieiras | 16 | 16 | 13 | 11 | 8 | 6 | 7 | 9 | 11 | 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 |