Last updated: July 2, 2025
In Santiago Nacaltepec, Mexico, awareness of the UV Index is crucial for protecting your skin against harmful rays. Understanding UV levels is essential not only for preventing sunburn, but also for maintaining long-term skin health. Nestled in a Cwb climate zone, Santiago Nacaltepec experiences significant UV exposure, especially during midday hours when levels can soar to 15—indicating an extreme risk of harm from unprotected sun exposure. By keeping an eye on the UV Index, residents and visitors alike can enjoy the beautiful outdoors while safeguarding their skin from potential damage.
The UV Index data paints a vibrant picture of sunlight intensity throughout the day. Beginning with a mild UVI of 1 at 7:00 AM, the day starts gently, gradually climbing to 3 by 9:00 AM. However, as the sun reaches its zenith, the UVI skyrockets, peaking at an intense 15 between 1:00 PM and 2:00 PM. During these hours, it's crucial to take protective measures against harmful UV rays. As the sun begins to set, the index dips, dropping to 5 by 5:00 PM and returning to a safer 1 by 7:00 PM. This fluctuation highlights the importance of staying sun-smart during peak hours, especially between 11:00 AM and 2:00 PM when the UVI is at its highest.
| 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 | 6 | high | 25 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 13 | extreme | 10 min |
| 13:00 | 15 | extreme | 10 min |
| 14:00 | 15 | extreme | 10 min |
| 15:00 | 13 | extreme | 10 min |
| 16:00 | 9 | very high | 15 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index exhibits a notable seasonal pattern, peaking during the warmer months from March to October, where values consistently remain in the extreme category (UV Index 14-15). The highest UV levels are recorded in April, May, June, and July, maintaining an extreme classification and a very short burn time of just 10 minutes. In contrast, January and December experience very high UV levels but with slightly longer burn times of 15 minutes. Based on this data, the high-risk months for UV exposure are clearly March through November, especially from April to August. Visitors and residents are advised to take precautionary measures during these months—such as wearing sunscreen, protective clothing, and seeking shade during peak hours—to minimize the risk of sunburn and long-term 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 |
| 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 |
| Santiago Nacaltepec | 10 | 13 | 14 | 15 | 15 | 15 | 15 | 14 | 14 | 13 | 11 | 9 |