Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of São Martinho, Portugal, where the sunny, mild climate can lead to significant UV exposure. As the UV Index peaks at 11 during the midday hours, awareness of UV levels becomes key in preventing sunburn and safeguarding skin health. With a characteristic Csb climate, São Martinho sees a spectrum of UV risks throughout the day, particularly in the summer months. By staying informed about the UV Index, you can better protect yourself and enjoy the beautiful outdoor environment safely.
The UV Index paints a vivid picture of the day's intensity, starting from a calm 0 at 7:00 AM and gradually building momentum. By 9:00 AM, it reaches a moderate 2, but the real surge comes as the sun climbs higher. At 11:00 AM, the index spikes to 6, followed by an impressive 8 at noon. The peak hits an exhilarating 11 at 2:00 PM—a reminder that sunscreen is a must! The intensity starts to wane thereafter, dropping to 6 at 5:00 PM and easing to 4 by 6:00 PM. As the day winds down, the UV rays fade, settling at a delicate 2 by 7:00 PM. Always stay sun-smart and enjoy the brightness!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 0 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 3 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 9 | very high | 15 min |
| 17:00 | 6 | high | 25 min |
| 18:00 | 4 | moderate | 30 min |
| 19:00 | 2 | low | 45 min |
Throughout the year, the UV Index demonstrates significant seasonal variation, with high-risk months primarily occurring from March to August when values reach their peak. Notably, May through July feature extreme UV Index levels (11-12), with a burn time as short as 10 minutes. This indicates that during these months, individuals should take extra precautions, such as wearing sunscreen, protective clothing, and seeking shade during peak sun hours. Conversely, in January and December, with a moderate UV Index of 4, burn times extend to 30 minutes, suggesting lower risk for sunburn. Visitors and residents are encouraged to remain vigilant and adjust their sun exposure habits in accordance with these fluctuations throughout the year to protect their skin health.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Braga UVI | 2 | 4 | 6 | 8 | 9 | 11 | 10 | 9 | 8 | 6 | 4 | 2 |
| Porto UVI | 2 | 4 | 6 | 8 | 9 | 11 | 10 | 9 | 8 | 6 | 4 | 2 |
| Amadora UVI | 3 | 5 | 6 | 9 | 10 | 11 | 10 | 9 | 8 | 6 | 4 | 3 |
| Lisbon UVI | 3 | 5 | 6 | 9 | 10 | 11 | 10 | 9 | 8 | 6 | 4 | 3 |
| Setubal UVI | 3 | 5 | 6 | 9 | 10 | 11 | 10 | 9 | 8 | 6 | 4 | 3 |
| Sao Martinho | 4 | 6 | 8 | 10 | 11 | 12 | 11 | 11 | 10 | 8 | 6 | 4 |