Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Castanhal, Brazil, where the tropical climate can lead to significant sun exposure. With UV levels peaking at 11 during midday, awareness of these levels is vital for preventing sunburn and protecting skin health. As Castanhal experiences high UV exposure, especially in the summer months, being informed about the UV Index helps you make safe choices for outdoor activities, ensuring that you enjoy the sun while safeguarding your skin. Stay smart and stay safe under the sun!
The UV Index throughout the day offers a clear picture of sun intensity and potential risk for skin exposure. Starting off at a mild level of 1 at 07:00, the index gradually climbs, reaching 2 by 08:00. By 09:00, it jumps to 4, signifying a need for sun protection as it approaches midday. The peak arrives at 11:00 with a striking 10, followed closely by 11 at both 12:00 and 13:00, indicating the highest risk for harmful UV rays. As the afternoon progresses, the UV Index dips, falling to 9 at 14:00 and eventually to a more manageable 5 by 15:00. The evening brings relief, as it decreases further to 3 at 16:00, and to 1 by 17:00. Finally, as the sun sets, the index drops to 0 by 19:00, marking the end of a day defined by varying levels of UV exposure. It's a vivid reminder of the sun's intensity and the importance of appropriate sun safety measures during peak hours!
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 | 10 | very high | 15 min |
12:00 | 11 | extreme | 10 min |
13:00 | 11 | extreme | 10 min |
14:00 | 9 | very high | 15 min |
15:00 | 5 | moderate | 30 min |
16:00 | 3 | moderate | 30 min |
17:00 | 1 | low | 45 min |
18:00 | 1 | low | 45 min |
19:00 | 0 | low | 45 min |
The UV Index demonstrates significant seasonal variations, with the highest values occurring from January to April, peaking at 16, indicating an extreme exposure category and a mere 10-minute burn time for unprotected skin. Throughout the year, the high-risk months remain consistent, with the UV Index consistently at 13 or above from January to May and returning to 13 from August to December, signifying continued high risk even in the latter part of the year. Visitors and residents are advised to exercise extreme caution during all months, especially from January to April, by applying broad-spectrum sunscreen, wearing protective clothing, and seeking shade to minimize harmful exposure to UV radiation.
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 |
Castanhal | 14 | 15 | 16 | 16 | 14 | 12 | 11 | 13 | 13 | 13 | 13 | 13 |