Last updated: July 2, 2025
In San Marcos, Texas, staying informed about the UV Index is crucial for safeguarding your skin and overall health. Understanding UV levels is essential not only for preventing painful sunburns but also for reducing long-term risks of skin damage and skin cancer. With a Cfa climate, San Marcos experiences significant sunlight and elevated UV exposure, particularly during midday hours when the UV Index peaks at 12. Being aware of these levels empowers residents and visitors alike to take proactive measures against harmful UV rays, ensuring outdoor activities remain enjoyable while prioritizing skin safety.
Today’s UV index presents a dynamic portrait of solar intensity, beginning with a gentle start at 07:00 and 08:00 with a rating of 1. As the day progresses, we witness a steady climb peaking at 12 during the afternoon hours of 13:00 and 14:00, indicating a very high risk of harm from unprotected sun exposure. The midday sun is at its fiercest, reaching a scorching 10 at 12:00, followed closely by an impressive 8 at 11:00. As afternoon transitions to evening, there’s a noticeable decline, dropping to 5 by 17:00 and gracefully winding down to 1 by 19:00. Stay sun-smart and ensure adequate protection during peak hours!
| 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 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 12 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index exhibits significant seasonal variation, with the highest levels typically occurring from April to September. During these months, the UV Index reaches extremes of 11 to 12, categorizing them as extreme exposure. February through October are considered high-risk months, especially April to August, where the burn time is as short as 10 minutes. It is vital for residents and visitors to take precautions, such as wearing sunscreen, protective clothing, and seeking shade during peak sunlight hours to minimize the risk of skin damage. As the UV Index decreases in the fall and winter months, November and December present lower risk, with more moderate values of 6 and 5, allowing for longer exposure times before burning occurs. Adjusting outdoor activities according to the UV index is essential for ensuring safety and health throughout the year.
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 | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 12 | 11 | 9 | 6 | 5 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |