Last updated: May 3, 2025
In San Antonio, awareness of the UV Index is crucial, as it plays a significant role in protecting skin health and preventing sunburn. With a Cfa climate, the city experiences intense sunlight, particularly during the summer months, leading to higher UV exposure risks. Understanding daily UV levels can help residents and visitors alike plan outdoor activities while minimizing harmful effects from the sun. When the UV Index peaks at 12 around midday, ensuring proper sun protection becomes essential to maintain healthy skin and enjoy San Antonio's sunny days safely.
The day begins gently with a UV Index of 1 at both 07:00 and 08:00, indicating minimal sun exposure. However, as the clock strikes 09:00, the index rises to 3, signifying a gradual increase in UV intensity. By 10:00, it reaches 5, and the sun takes center stage at 11:00 with a striking 8. The peak arrives at 12:00, soaring to an impressive 10, and continues to climb, hitting its pinnacle with a dazzling 12 at 13:00. As the afternoon unfolds, values begin a slow descent: 11 at 14:00, 10 at 15:00, and then dropping to 7 by 16:00. The evening brings relief, with the index tapering down to 4 at 17:00, 2 at 18:00, and finally returning to a safe 1 by 19:00. Remember to stay protected during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 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 | 11 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV levels exhibit significant seasonal changes. January sees a moderate UV Index of 5, while February and March jump to 8 and 9, respectively, indicating very high exposure risks with short burn times of just 15 minutes. The peak months for UV exposure are from April to August, where the Index reaches an extreme level of 11 to 12, necessitating caution with a burn time of only 10 minutes. As the year progresses, UV levels decrease, but October remains notably high at 9, followed by November with a high category of 7. For visitors and residents alike, it is crucial to take protective measures during the high-risk months of April through September and remain vigilant, using sunscreen, wearing protective clothing, and seeking shade to minimize the risk of skin damage.
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 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |
| San Antonio | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 12 | 11 | 9 | 7 | 5 |