Last updated: August 1, 2025
Awareness of the UV Index is crucial for residents and visitors in Sienes, Spain, as it plays a vital role in protecting skin health and preventing sunburn. Understanding UV levels can help you make informed decisions about outdoor activities, especially during the peak hours when the UV Index reaches its highest levels, with a maximum of 11 at 2 PM. Situated in a temperate oceanic climate (Cfb), Sienes experiences notable sunshine, making it essential to be cautious of UV exposure risks, particularly in the summer months. By staying informed about UV Index readings, you can enjoy the beautiful Spanish outdoors while safeguarding your skin!
As the day unfolds, the UV Index rises dramatically, starting at a modest 1 by 07:00 and steadily climbing to a peak of 11 between 14:00 and 15:00. This surge highlights the importance of staying protected under the sun, especially from 12:00 to 15:00, when the index exceeds 8—a strong indicator of harmful UV exposure. After this midday peak, the index gradually declines, settling back to 4 by 18:00 and dipping to 2 by 19:00. Those planning outdoor activities should take precautions during the most intense hours when the sun's rays are the strongest, ensuring a safe and enjoyable experience in the sun.
| 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 | 3 | moderate | 30 min |
| 11:00 | 5 | moderate | 30 min |
| 12:00 | 7 | high | 25 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 8 | very high | 15 min |
| 17:00 | 6 | high | 25 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 2 | low | 45 min |
The UV Index shows significant seasonal variation, with the highest values occurring during the summer months. From March to August, the UV Index climbs from 6 in March to a peak of 11 in both June and July, indicating extreme exposure risks and a burn time as short as 10 minutes. April and May also present very high risks, with indices of 9 and 10, respectively. In contrast, the UV Index drops to moderate levels during the winter months, specifically in January, February, and November, with values ranging from 2 to 4, where burn times extend from 30 to 45 minutes. As such, it is crucial for visitors and residents to exercise extra caution during the high-risk months of April to August, by wearing sunscreen, hats, and protective clothing, and limiting outdoor activities during peak sun hours to avoid harmful solar exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Barcelona UVI | 3 | 4 | 5 | 7 | 8 | 10 | 10 | 9 | 7 | 6 | 3 | 2 |
| Zaragoza UVI | 3 | 4 | 6 | 8 | 9 | 11 | 11 | 9 | 8 | 6 | 3 | 2 |
| Valencia UVI | 3 | 4 | 6 | 8 | 9 | 11 | 10 | 9 | 8 | 6 | 4 | 3 |
| Madrid UVI | 3 | 4 | 6 | 8 | 10 | 11 | 11 | 9 | 8 | 6 | 4 | 3 |
| Sienes | 3 | 4 | 6 | 9 | 10 | 11 | 11 | 10 | 8 | 6 | 4 | 2 |
| Sevilla UVI | 3 | 5 | 7 | 9 | 10 | 11 | 10 | 10 | 9 | 7 | 4 | 3 |