Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of El Fresno, Mexico, where the combination of a Cwb climate and high UV exposure can pose significant health risks. With UV levels peaking at a staggering 11 during midday, awareness of these fluctuations is essential for sunburn prevention and maintaining optimal skin health. By staying informed about daily UV variations, you can take proactive measures to protect yourself against harmful rays, especially in a region where the sun's intensity can change dramatically throughout the day. Whether you're enjoying outdoor activities or simply stepping out for errands, keeping an eye on the UV Index ensures you stay safe and healthy under the Mexican sun.
The UV Index reveals a dramatic rise in solar intensity as the day progresses. Starting at a low value of 0 at 7:00 AM, it gently climbs to 1 by 8:00 AM. However, by 10:00 AM, the index surges to 5, signaling the onset of midday sun. The peak intensity is reached between 12:00 PM and 2:00 PM, where the UV Index hits a remarkable 13, indicating a high risk of harm from unprotected sun exposure. As the afternoon wanes, the index gradually declines, dropping to 9 by 4:00 PM and tapering down to 1 by 7:00 PM. This hourly data serves as a crucial reminder to stay protected during those peak hours, especially when the UV Index is at its highest.
| 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 | 13 | extreme | 10 min |
| 14:00 | 13 | extreme | 10 min |
| 15:00 | 12 | 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 experiences significant fluctuations throughout the year, with the highest values occurring between February and September. During these months, particularly from March to May, the index reaches extreme levels, peaking at 15 in May. January, November, and December show relatively high UV readings, with a "very high" exposure category, but the risk of sunburn is notably lower, allowing for 15 minutes of safe exposure. Visitors and residents are strongly advised to take precautions during high-risk months by seeking shade, wearing protective clothing, and applying sunscreen every two hours to minimize the risk of skin damage. Stay vigilant, as even short exposure times can be harmful during peak UV periods.
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 |
| El Fresno | 9 | 11 | 14 | 14 | 15 | 14 | 13 | 13 | 14 | 12 | 10 | 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 |