Last updated: August 1, 2025
In San Juan (Las Joyas), Mexico, understanding the UV Index is crucial for maintaining your skin health and preventing sunburn. With a warm climate characterized by high UV exposure, particularly between 10 AM and 2 PM, residents and visitors alike should be vigilant about their time in the sun. The UV Index can peak at 14, indicating a very high risk of harm from unprotected sun exposure, emphasizing the need for effective sun protection measures. By staying informed about UV levels, you can enjoy the sunny beauty of San Juan while safeguarding your skin from potential damage.
As the sun rises, the UV Index begins at a moderate level of 0 at 7:00 AM. By 8:00 AM, it climbs to 1, indicating a low risk for sunburn. The intensity increases steadily, reaching 5 by 10:00 AM, where precautions start to become advisable. The peak arrives startlingly at 12 PM, with a significant UV Index of 12, marking a high risk of harm from unprotected sun exposure. From 1 PM to 2 PM, the index remains at its highest, 14, urging outdoor enthusiasts to seek shade or wear protective gear. A gradual decline begins by 3 PM with 13, tapering off to 6 by 5 PM. As the afternoon transitions into evening, the UV Index lowers to 3 at 6 PM, and concludes at a very manageable 1 by 7 PM. This pattern highlights the critical importance of sunscreen and protective clothing during midday outdoor activities.
| 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 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 14 | extreme | 10 min |
| 14:00 | 14 | extreme | 10 min |
| 15:00 | 12 | 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 readings exhibit significant seasonal variation, with the highest levels occurring from March to September where the index consistently reaches 14 and is classified as extreme. January and November present very high indices of 10, with a burn time of 15 minutes, while December features a slightly lower index of 9. Visitors and residents are particularly at risk during the months of February through October, where the burn time drastically shortens to just 10 minutes due to the extreme UV exposure. It is essential for individuals to take proactive measures during these high-risk months by wearing protective clothing, applying sunscreen, and seeking shade to reduce the risk of skin damage.
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 |
| San Juan (Las Joyas) | 10 | 12 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 12 | 10 | 9 |
| Puebla UVI | 10 | 12 | 14 | 15 | 15 | 15 | 15 | 14 | 14 | 13 | 10 | 9 |