Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of San Francisco de las Mesillas, Mexico, as it directly impacts skin health and sunburn prevention. With a predominantly Am climate, the region experiences significant UV exposure—especially during peak hours when the index can soar to a maximum of 14. By staying informed about UV levels, you can better protect yourself and your loved ones from harmful effects of sun exposure, ensuring a safer and more enjoyable outdoor experience.
As the sun rises, the UV Index begins at a mild 1 at 7:00 AM and remains low until 9:00 AM, when it escalates to 3. The real intensity kicks in around 10:00 AM, reaching 5, and the index climbs dramatically as the day progresses. By 12:00 PM, it peaks at a scorching 12, and an impressive 14 is recorded at both 1:00 PM and 2:00 PM. The sun starts to wane after that, with the index gradually dipping to 8 by 4:00 PM, before descending to a gentle 2 by 6:00 PM. The day concludes with a return to a low 1 at 7:00 PM, making it clear that midday sun poses the greatest danger – a reminder of the importance of sun protection during those peak hours.
| 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 | 5 | moderate | 30 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 14 | extreme | 10 min |
| 14:00 | 14 | extreme | 10 min |
| 15:00 | 12 | extreme | 10 min |
| 16:00 | 8 | very high | 15 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Seasonal UV changes indicate that the highest levels of UV exposure occur from February to October, with a peak UV Index of 14 in both June and July, where the burn time is only 10 minutes. The months of March through October are categorized as extreme, posing significant risks for sunburn and skin damage. January, November, and December feature lower UV levels, with burn times extending to 15 minutes but still classified as very high. Visitors and residents should take precautions during the high-risk months, including wearing sunscreen, protective clothing, and seeking shade, particularly during midday hours when the sun's intensity is greatest. Prioritizing skin protection is essential to prevent harmful effects from overexposure to UV radiation.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| San Francisco de las Mesillas | 9 | 11 | 13 | 13 | 13 | 14 | 14 | 13 | 13 | 11 | 9 | 8 |
| 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 |