Last updated: June 2, 2025
Understanding the UV Index in Guanajuato, Mexico, is crucial for protecting your skin and health against the sun's powerful rays. With a BWh climate characterized by warm, dry conditions, residents and visitors alike need to be aware of the varying UV levels throughout the day. By grasping the significance of these levels, you can take essential steps to prevent sunburn and long-term skin damage. Notably, during peak hours—between 11 AM and 1 PM—the UV Index can reach a staggering 11, indicating an extreme risk of harm from unprotected sun exposure. Stay informed and enjoy the sunshine safely!
At dawn, the UV Index begins its ascent with a mild 1 at 7:00 AM, gradually increasing to a moderate 2 by 8:00 AM. As the sun climbs higher, it reaches a noteworthy 5 at 9:00 AM, but the real intensity hits at 10:00 AM with a strong 7. By 11:00 AM, the UV levels soar to a peak of 10, continuing at an impressive 11 from 12:00 PM to 1:00 PM—the highest of the day. After this midday intensity, the numbers begin to wane, dropping to 10 at 2:00 PM, then to 8 at 3:00 PM. The afternoon cools off slightly, falling to 5 by 4:00 PM, and ultimately settling back to 3 by 5:00 PM. As the day draws to a close, the UV Index gently slips to 1 by 6:00 PM, and remains there until 7:00 PM, indicating a safe return to evening activities.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 7 | high | 25 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index shows significant seasonal variation, with the highest levels occurring from March to August. During these months, particularly April through July, the UV Index reaches a peak of 12 in July, categorized as extreme, allowing only a 10-minute burn time for unprotected skin. February also sees elevated levels with a high UV Index of 6. To ensure safety, visitors and residents should take extra precautions during the high-risk months of March, April, May, June, July, and August, when the risk of skin damage from sun exposure is at its highest. It is advisable to wear protective clothing, apply sunscreen, and seek shade during peak hours to minimize the risk of sunburn. As UV levels decrease in the fall and winter months, from September to December, individuals can enjoy more moderate exposure with indices dropping back to 4 or 5, indicating moderate risk and longer burn times of 30 minutes.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Guanajuato | 4 | 6 | 9 | 10 | 11 | 11 | 12 | 11 | 10 | 8 | 5 | 4 |
| 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 |