Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Castilho, Brazil, where the tropical climate can bring varying levels of ultraviolet radiation throughout the day. Awareness of UV levels plays a vital role in preventing sunburn and maintaining overall skin health, particularly during peak hours when the index climbs to a high of 8 between noon and 1 PM. With predominant sunlight in the region, it's essential for everyone to recognize the potential risks associated with UV exposure, ensuring they take appropriate protective measures to enjoy the beautiful Brazilian sun safely.
As the sun rises, the UV Index begins its ascent, starting at a gentle 1 by 7:00 AM and remaining low at 8:00 AM. By 9:00 AM, it edges up to 2, but the real intensity kicks in at 10:00 AM with a surge to 4. The peak occurs around 12:00 PM and 1:00 PM, where it reaches a scorching 8, representing a significant rise in UV exposure. As the afternoon unfolds, the index begins its descent, dropping to 6 by 2:00 PM and easing to 4 by 3:00 PM. Before the sun sets, the UV levels taper off quickly, with readings of 2 at 4:00 PM and declining to 0 by 6:00 PM. This hourly data serves as a reminder to stay protected during peak UV hours, particularly between 11:00 AM and 1:00 PM.
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 | 7 | high | 25 min |
12:00 | 8 | 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 seasonal UV changes indicate that exposure levels are consistently high, particularly from January to April, where the UV Index remains in the extreme category, peaking at 16 in February and December. High-risk months include January, February, March, April, September, October, and November, as they all feature an extreme UV Index that can lead to sunburn in as little as 10 minutes. Conversely, the summer months of May, June, July, and August experience a drop to very high and high categories, with slightly longer burn times of 15 to 25 minutes. Visitors and residents should take precautions during all months, especially in extreme UV conditions, by seeking shade, wearing protective clothing, and applying broad-spectrum sunscreen to minimize the risk of skin damage.
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 |
Castilho | 15 | 16 | 13 | 11 | 8 | 7 | 8 | 10 | 12 | 14 | 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 |