Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of Santo Tomas de Arriba, Mexico—a region known for its BSh climate, where the sun's intensity can soar dramatically. Awareness of UV levels is essential not only for preventing painful sunburns but also for safeguarding your long-term skin health. With peak UV levels reaching up to 15 between the hours of 1 PM and 2 PM, it's important to understand the risks associated with prolonged exposure during these hours. Equip yourself with this knowledge to enjoy the beautiful sunny days in Santo Tomas de Arriba while protecting your skin from harmful rays.
The UV Index data paints a vibrant picture of sunlight intensity throughout the day. Beginning with a mild UVI of 1 at 7:00 AM, the day starts gently, gradually climbing to 3 by 9:00 AM. However, as the sun reaches its zenith, the UVI skyrockets, peaking at an intense 15 between 1:00 PM and 2:00 PM. During these hours, it's crucial to take protective measures against harmful UV rays. As the sun begins to set, the index dips, dropping to 5 by 5:00 PM and returning to a safer 1 by 7:00 PM. This fluctuation highlights the importance of staying sun-smart during peak hours, especially between 11:00 AM and 2:00 PM when the UVI is at its highest.
| 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 | 6 | high | 25 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 13 | extreme | 10 min |
| 13:00 | 15 | extreme | 10 min |
| 14:00 | 15 | extreme | 10 min |
| 15:00 | 13 | extreme | 10 min |
| 16:00 | 9 | very high | 15 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV Index levels exhibit significant fluctuations, with the highest risk occurring from February to November, where the index remains consistently high or extreme, particularly in March, April, May, July, and August, reaching peaks of 14 to 15. During these months, the burn time is notably short, at just 10 minutes, emphasizing the necessity for proactive sun protection. Conversely, January and December show slightly lower indices of 10 and 9, respectively, classifying them as very high risk months with a 15-minute burn time. To ensure safety, residents and visitors should diligently apply sunscreen, wear protective clothing, and limit sun exposure during peak hours, especially from late winter through early fall.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 |
| Santo Tomas de Arriba | 10 | 13 | 14 | 15 | 15 | 14 | 15 | 14 | 14 | 13 | 11 | 9 |