Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of San Sebastian del Sur, Mexico, where the sun shines brightly in a Csa climate zone. Being aware of the UV levels not only helps prevent sunburn but also plays a pivotal role in maintaining long-term skin health. With peak UV exposure reaching as high as 13 during midday, it's essential to protect yourself, especially when engaging in outdoor activities. Knowing when to seek shade or apply sunscreen can make all the difference in enjoying this beautiful coastal town while keeping your skin safe from harmful UV radiation.
As the sun rises, the UV Index begins its ascent, starting at a cool 0 by 07:00 AM. By 08:00 AM, it nudges up to 1, a gentle reminder of the UV rays to come. The intensity escalates quickly, hitting 2 by 09:00 AM and reaching 4 at 10:00 AM. Peak intensity is felt at 12:00 PM when it soars to an impressive 10, and it climaxes at 13:00 PM with a formidable 13—elicit caution for sun exposure. As the afternoon unfolds, the index slowly declines, tapering to 12 at 15:00 PM, then 10 by 16:00 PM. The late hours offer some respite, as it decreases to 6 at 17:00 PM, before settling back to a manageable 3 by 18:00 PM and dropping to 1 as the day draws to a close at 19:00 PM. Be sure to take advantage of the earlier hours to enjoy sunshine safely! 🌞
| 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 | 10 | 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, UV Index levels demonstrate significant seasonal fluctuations, peaking during the spring and summer months. From February to October, the UV Index consistently remains in the extreme exposure category, with the highest readings in March to June, where it reaches an index of 14 to 15 and a burn time of just 10 minutes. These months, particularly March through September, are deemed high-risk for UV exposure. As a result, residents and visitors should take extra precautions during these periods, including wearing protective clothing, applying broad-spectrum sunscreen, and seeking shade when outdoors. In contrast, January, November, and December see a drop to the very high category, allowing for slightly longer burn times of 15 minutes, yet vigilance remains important year-round.
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 |
| San Sebastian del Sur | 9 | 11 | 14 | 14 | 14 | 15 | 13 | 13 | 14 | 12 | 10 | 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 |