Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of San Marcos, as it directly impacts sun safety and skin health. With peak UV levels reaching a critical 11 during the midday hours, awareness is essential to prevent sunburn and long-term skin damage. This charming city, nestled in a Mediterranean climate (Csa) zone, tends to experience higher UV exposure risks, especially in the summer months. By staying informed about daily UV readings, you can enjoy the sun's rays while protecting your skin!
As the sun rises, the UV Index gradually climbs, starting at a low level of 1 at 07:00 and reaching a modest 2 by 08:00. However, by mid-morning, it surges to an impactful 4 at 09:00 and continues to rise dramatically. Peak intensity occurs at 12:00 and 13:00, with a staggering index of 11, indicating a significant risk of harm from unprotected sun exposure. Following this high, the index begins its descent, dropping to 10 at 14:00 and tapering off to a moderate level of 6 by 16:00. As the day winds down, the UV Index settles back to a low 1 by 18:00 and maintains this level through the evening hours. It's a day where sun safety is paramount during the midday 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 | 9 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV exposure varies significantly, with the highest UV Index levels observed from March to August. The months of May and June peak at an extreme UV Index of 11 and 12, where the burn time drops to just 10 minutes, posing a significant risk for sunburn. March and April also present substantial risks, classified as very high with an Index of 9 and 10, and a burn time of 15 minutes. As summer wanes into autumn, the UV Index begins to decrease, but September and October still remain at high levels with burn times of 15 to 25 minutes. Therefore, visitors and residents are strongly advised to prioritize sun safety, especially during the high-risk months of March through August by wearing protective clothing, using sunscreen, and seeking shade during peak sun hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago UVI | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| Brooklyn UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| New York City UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| San Marcos | 4 | 6 | 9 | 10 | 11 | 12 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |