Last updated: July 2, 2025
In Justo Sierra, Mexico, staying informed about the UV Index is crucial for maintaining skin health and preventing sunburns. Understanding UV levels empowers residents and visitors alike to make smart choices about sun exposure, especially in this region known for its tropical climate. With midday UV levels peaking at an intense 15, it's vital to protect your skin, as the risk of harmful effects escalates significantly. Whether you're enjoying outdoor activities or simply going about your day, being aware of the UV Index can help you safeguard your health against potential damage. Remember, staying educated about UV exposure is not just a good habit; it's essential for thriving under the sun!
As the sun rises, the UV Index starts off low, peaking at 1 from 7:00 AM to 9:00 AM. However, by 10:00 AM, it takes a noticeable leap to 7, signaling stronger rays. The intensity continues to rise, reaching its zenith at 12:00 PM with a staggering 14, and then hitting its peak at 1:00 PM at 15—a clear reminder to seek shade and protect your skin. The index gradually declines throughout the afternoon, dropping to 11 by 3:00 PM, and easing into the evening with values of 4 at 5:00 PM, 2 by 6:00 PM, and reverting back to 1 by 7:00 PM. Be mindful of the sun during peak hours, especially between 10:00 AM and 2:00 PM, when the UV exposure is at its maximum!
| 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 | 7 | high | 25 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 14 | extreme | 10 min |
| 13:00 | 15 | extreme | 10 min |
| 14:00 | 14 | extreme | 10 min |
| 15:00 | 11 | extreme | 10 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, the UV Index in this region exhibits significant seasonal changes, with high-risk months predominantly from January to October. Notably, from March to June, the UV Index peaks at 15, categorized as extreme, signifying that unprotected skin can burn in as little as 10 minutes. February and March see the highest readings—reaching 13 and 15, respectively—while August and September maintain a high index at 14. As a result, it is crucial for visitors and residents to take adequate precautions during these months, such as wearing sunscreen, protective clothing, and seeking shade, especially during midday hours when UV exposure is most intense. In contrast, while December presents a slightly lower risk with a UV Index of 10, it is still advisable to remain vigilant.
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 |
| Justo Sierra | 11 | 13 | 15 | 15 | 15 | 15 | 15 | 14 | 14 | 13 | 11 | 10 |