Last updated: July 2, 2025
In the picturesque city of Blumenau, Brazil, understanding the UV Index is essential for protecting your skin and wellbeing. With ultraviolet radiation peaking between 10 AM and 2 PM, awareness of UV levels can significantly reduce the risk of sunburn and long-term skin damage. Blumenau, characterized by its Cfa climate, experiences varying UV exposures throughout the day, highlighting the need for vigilance during peak hours when the index can reach 6. Staying informed about these levels empowers residents and visitors alike to enjoy the beauty of the outdoors while prioritizing skin health.
The UV Index over the day shows a dynamic range of exposure, starting off calm in the early hours. At 07:00 and 08:00, it remains at a gentle 1, perfect for a leisurely morning. As the sun climbs higher, the index rises steadily, reaching 2 by 09:00 and peaking at 6 around 12:00, indicating caution is necessary for outdoor activities. The intensity slightly dips from there, down to 5 by 13:00 and then to 4 at 14:00, before gradually decreasing to 1 by 16:00. Finally, the UV exposure diminishes to 0 by 18:00, signaling a safe end to the day. Stay mindful of those peak hours for a fun and safe experience in the sun!
| 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 | 3 | moderate | 30 min |
| 11:00 | 5 | moderate | 30 min |
| 12:00 | 6 | high | 25 min |
| 13:00 | 5 | moderate | 30 min |
| 14:00 | 4 | moderate | 30 min |
| 15:00 | 3 | moderate | 30 min |
| 16:00 | 1 | 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 fluctuations throughout the year, with the highest levels occurring during the winter months of January, February, and March, where it reaches an extreme rating of 15 and a quick burn time of just 10 minutes. As the seasons change, April sees a slight decrease to 10 (very high), while May and June drop further to 7 and 6, both categorized as high, allowing for longer exposure times of 25 minutes. However, August sees an uptick to 8, returning to a very high level, before reverting to extreme conditions again in September (UV Index 11) and October (13). November and December mirror the start of the year with extreme values of 14 and 15, respectively. Visitors and residents alike should be particularly cautious during high-risk months (January, February, March, September, October, November, and December), limiting sun exposure to prevent harmful effects. Utilizing protective clothing, sunglasses, and sunscreen is strongly advised, especially during peak UV hours to maintain skin health.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Blumenau | 15 | 14 | 12 | 10 | 7 | 6 | 6 | 8 | 11 | 13 | 14 | 15 |
| 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 |