Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Colonia 18 de Marzo, Mexico, where the sun’s intensity can pose significant risks to skin health. With a tropical climate that often leads to high UV levels, awareness of these indicators helps in preventing sunburns and reducing the long-term risk of skin damage. During peak hours—especially from noon to 2 PM—UV Index values can soar above 11, indicating a very high risk of harm from unprotected sun exposure. Stay informed and protect your skin while enjoying the beautiful, sunny days in Colonia 18 de Marzo!
The UV Index throughout the day reveals a dynamic pattern of sun exposure. Starting at 07:00, the index is at a minimal 0, indicating that the sun's rays are weak. As the morning progresses, it climbs to 2 by 09:00 and reaches 4 by 10:00, suggesting that protective measures should start to be considered. The intensity peaks dramatically around noon, hitting a staggering 11 at 12:00, followed closely by a maximum of 13 from 13:00 to 14:00. During these hours, it’s crucial to seek shade and apply sunscreen. As the afternoon wanes, the index gradually dips to 9 at 16:00 and continues to fall, settling at 1 by 19:00, marking a safe return for evening activities. Overall, it's clear that midday hours demand the most caution under the sun!
| 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 | 4 | moderate | 30 min |
| 11:00 | 7 | high | 25 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 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
The seasonal UV changes indicate a significant increase in UV Index values from January to October, peaking at 14 during the months of March through June, categorized as extreme exposure with a burn time of only 10 minutes. Following this peak, UV levels gradually decrease but remain high in the late summer and early fall months, notably staying in the 13 range from July to September, before dropping to 12 in October. November and December see a return to very high levels, with indices of 9 and 8 respectively, allowing for slightly longer burn times of 15 minutes. As a result, it is crucial for both visitors and residents to take precautions during the high-risk months of February through October by wearing appropriate sun protection, seeking shade, and limiting sun exposure, especially during peak hours, to minimize 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 |
| Colonia 18 de Marzo | 9 | 11 | 14 | 14 | 14 | 14 | 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 |