Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors in Castillos, Uruguay, where the climate combines warm summers with ample sunlight. As you enjoy the beautiful outdoors, staying informed about UV levels can play a vital role in preventing sunburn and protecting your skin health. During the peak hours of midday, the UV Index can reach levels of 4, indicating a moderate risk of harm from unprotected sun exposure. With Castillos’ typical sunny conditions, being aware of these risks helps ensure you can savor the local beauty while safeguarding your skin.
The UV Index for the day unfolds a fascinating journey through the hours, starting with a maximum of 0 at 7:00 AM, indicating a safe start to the morning. As the sun ascends, the index gradually climbs to 1 by 8:00 AM and 9:00 AM, hinting at a gentle rise in UV exposure. By 10:00 AM, the UV Index reaches 2, marking the beginning of a moderate risk period. The intensity peaks at 12:00 PM with a high of 4, prompting sun safety measures to avoid overexposure. As the afternoon progresses, the index recedes slightly, stabilizing at 3 from 11:00 AM to 14:00 PM, before tapering off to 1 by 16:00 PM, and finally returning to 0 by the evening. This daily UV cycle highlights the importance of sun safety, especially during midday hours when UV radiation is strongest.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 0 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 1 | low | 45 min |
| 10:00 | 2 | low | 45 min |
| 11:00 | 3 | moderate | 30 min |
| 12:00 | 4 | moderate | 30 min |
| 13:00 | 3 | moderate | 30 min |
| 14:00 | 3 | moderate | 30 min |
| 15:00 | 2 | low | 45 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 |
Throughout the year, UV Index values exhibit significant seasonal fluctuations, with the highest readings occurring from January to March and October to December. These months are categorized as having an extreme exposure level, with a rapid burn time of just 10 minutes, posing substantial risks for skin damage. Conversely, from April to August, the UV Index decreases, transitioning to high and moderate levels, allowing for longer exposure times of 25 to 30 minutes before burning occurs. Notably, September presents a spike back to a very high index. Given these trends, it is advisable for visitors and residents to exercise increased caution during high-risk months (particularly January, February, March, October, November, and December) by wearing protective clothing, applying broad-spectrum sunscreen, and seeking shade during peak hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Las Piedras UVI | 14 | 13 | 11 | 7 | 5 | 3 | 4 | 6 | 8 | 10 | 13 | 14 |
| Montevideo UVI | 14 | 13 | 11 | 7 | 5 | 3 | 4 | 6 | 8 | 10 | 13 | 14 |
| Castillos | 14 | 13 | 11 | 7 | 5 | 4 | 4 | 6 | 8 | 11 | 13 | 14 |
| Paysandu UVI | 15 | 13 | 11 | 8 | 5 | 4 | 4 | 6 | 8 | 11 | 13 | 14 |
| Salto UVI | 15 | 13 | 12 | 8 | 5 | 4 | 5 | 6 | 9 | 11 | 13 | 14 |
| Rivera UVI | 15 | 14 | 12 | 9 | 5 | 4 | 5 | 7 | 9 | 12 | 14 | 15 |