Last updated: July 2, 2025
In San Francisco, Mexico, understanding the UV Index is essential for safeguarding your skin and overall health. As the sun's rays can cause sunburn and long-term skin damage, being aware of UV levels helps you take the necessary precautions. The city's climate, characterized by its warm and sunny days, presents unique exposure risks, particularly from late morning to early afternoon when the UV Index peaks at 12. By staying informed about the UV Index, you can enjoy the beautiful weather while protecting yourself from harmful effects, ensuring vibrant skin health for years to come.
As the sun rises, the UV Index gradually climbs, starting at a safe 0 at 7:00 AM. By 8:00 AM, it reaches a mild 1, still a good time for outdoor enthusiasts to enjoy the morning. Things heat up more substantially by 10:00 AM with a 3, reaching a noticeable 6 by 11:00 AM. The intensity peaks at 12:00 PM, hitting a height of 9, and continues to soar to an impressive 12 at 1:00 PM—the prime hour for sun exposure. As the afternoon unfolds, the UV Index starts to decline, maintaining a strong 11 at 2:00 PM before tapering off. By 5:00 PM, it drops to 6, and as the sun sets, it relaxes back down to 3 at 6:00 PM, finally resting at 1 by 7:00 PM. It's vital to stay protected during those peak hours!
| 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 | 9 | very high | 15 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 12 | extreme | 10 min |
| 15:00 | 11 | extreme | 10 min |
| 16:00 | 9 | very high | 15 min |
| 17:00 | 6 | high | 25 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
The UV Index exhibits significant seasonal variation, with the highest levels occurring from March to October, where exposure categories reach extreme status. March through August sees consistently high UV Index ratings of 12-13, resulting in a minimal burn time of just 10 minutes. Visitors and residents should be particularly cautious during these months, as the risk of sunburn is substantial. January and February also pose a risk with UV Index values near 10, categorized as very high, leading to a burn time of 15 minutes. As the seasons transition into November and December, the UV Index drops, but care should still be exercised. November has a UV Index of 9 (very high) with a burn time of 15 minutes, and December sees a further decrease to 7 (high), allowing for a slightly longer burn time of 25 minutes. To ensure safety, it is advisable to wear sunscreen, seek shade, and wear protective clothing during the high-risk months, especially from March to October when sun exposure can lead to serious skin damage in a short amount of time.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| San Francisco | 8 | 10 | 12 | 13 | 13 | 13 | 12 | 13 | 12 | 11 | 9 | 7 |
| Guadalajara UVI | 9 | 11 | 14 | 14 | 14 | 13 | 13 | 13 | 13 | 12 | 9 | 8 |
| Iztapalapa UVI | 10 | 12 | 14 | 15 | 14 | 14 | 14 | 14 | 14 | 12 | 10 | 8 |
| Ecatepec de Morelos UVI | 10 | 12 | 14 | 15 | 15 | 14 | 14 | 13 | 14 | 12 | 10 | 8 |
| Mexico City UVI | 10 | 12 | 14 | 15 | 15 | 14 | 14 | 13 | 14 | 12 | 10 | 8 |
| Puebla UVI | 10 | 12 | 14 | 15 | 15 | 15 | 15 | 14 | 14 | 13 | 10 | 9 |