Last updated: August 1, 2025
Understanding the UV Index in San Francisco, Mexico is essential for anyone looking to enjoy the sun safely. As the UV levels can soar to dangerous heights, with a peak of 12 around noon, being informed helps prevent sunburn and protects your skin health over time. The city's unique climate, characterized by warm days and sunny spells, can lead to increased UV exposure, making it crucial to monitor these levels. By staying aware of the UV Index, you can make smarter choices about sun protection and enjoy all that San Francisco has to offer without compromising your health.
The UV Index today tells a compelling story of the sun's intensity as it rises and falls throughout the day. At 07:00, we start with a gentle UVI of 1, gradually climbing to 2 by 08:00. As the clock strikes 09:00, the intensity ramps up to 4, but it's not until 10:00 that we hit a significant level of 7. Midday thrill peaks at 12:00 with a commanding UVI of 12, remaining steady until 13:00 before it begins to wane. The afternoon brings a slight decline, with values decreasing to 9 at 15:00 and ultimately settling at a low 1 by 19:00 as the sun sets. This pattern underscores the importance of seeking shade and applying sunscreen during peak hours to enjoy the sun's warmth safely!
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 | 10 | very high | 15 min |
12:00 | 12 | extreme | 10 min |
13:00 | 12 | extreme | 10 min |
14:00 | 11 | extreme | 10 min |
15:00 | 8 | very high | 15 min |
16:00 | 5 | moderate | 30 min |
17:00 | 3 | moderate | 30 min |
18:00 | 1 | low | 45 min |
19:00 | 1 | low | 45 min |
The UV Index demonstrates significant seasonal changes, with high-risk months identified from March to October, where the index reaches extreme levels. In these months, the UV Index peaks at 13 in April, May, and June, corresponding to a burn time of only 10 minutes. Even in January and February, the UV Index remains notably high at 8 and 10, making these months also pose risks. As fall approaches, the index begins to decline, dropping to 11 in October and further down to 8 and 7 during November and December, with longer burn times of 15 and 25 minutes respectively. For both visitors and residents, it is crucial to take precautions during the high-risk months, including applying broad-spectrum sunscreen, wearing protective clothing, and seeking shade, especially during midday hours to reduce the risk of sunburn and long-term skin damage.
UV Risk Categories
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
San Francisco | 8 | 10 | 12 | 13 | 13 | 13 | 12 | 12 | 12 | 11 | 8 | 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 |