Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of El Castillo, Mexico, where the Cwa climate brings warm, sunny days, particularly during peak summer months. Awareness of UV levels plays a vital role in preventing sunburn and maintaining skin health, as prolonged exposure to high UV radiation can lead to serious skin damage. Throughout the day, the UV Index in El Castillo spikes significantly, peaking at a hazardous level of 13 around midday. This highlights the importance of taking protective measures, such as seeking shade, wearing sunscreen, and donning protective clothing, especially when outdoor activities are on the agenda. Staying informed about UV exposure risks can help you enjoy the beautiful Mexican sun while keeping your skin safe.
The UV index throughout the day reveals a dynamic pattern, starting from a low 0 at 7:00 AM and gradually climbing as the sun rises. By 10:00 AM, it reaches 4, signaling the start of potential sun sensitivity. As noon approaches, the intensity peaks dramatically at 12:00 PM with a UV index of 10, which is considered very high, urging outdoor enthusiasts to take protective measures. The afternoon hours continue to show significant UV levels, with a maximum of 13 at 1:00 PM and 2:00 PM, before slowly tapering off in the later afternoon and evening, dropping back to 1 by 7:00 PM. This data emphasizes the importance of sun safety, especially during the midday hours when UV exposure poses the greatest risk.
| 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 | 10 | very high | 15 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 |
Throughout the year, the UV Index exhibits significant seasonal variations, peaking during the spring and summer months. From February through August, the UV Index consistently reaches extreme levels (11-14), with the highest values recorded in March, April, May, and August. Notably, October also remains at an extreme level (12), indicating potential for harmful UV exposure. The high-risk months for UV exposure are thus identified as February through August, where the advised burn time is only 10 minutes. In contrast, January, November, and December present lower UV levels (with indices of 9 and 8), classified as very high, allowing for a slightly longer exposure time of 15 minutes. Visitors and residents are strongly advised to take protective measures, such as wearing sunscreen, protective clothing, and seeking shade during peak UV hours, particularly from late winter through summer.
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 Castillo | 9 | 11 | 14 | 14 | 14 | 14 | 13 | 14 | 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 |