Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in San Marcos, Guatemala, where the Aw climate brings warm temperatures and high levels of sun exposure. With UV Index readings peaking at 15 during midday, awareness of the UV levels can significantly aid in preventing sunburn and protecting skin health. Knowing when to seek shade or apply sunscreen not only enhances your outdoor experience but also safeguards against long-term skin damage. Given that San Marcos experiences intense sunlight, particularly between 10 AM and 2 PM, keeping an eye on the UV Index is essential for enjoying the beautiful outdoors safely.
At sunrise, the UV Index begins at a modest 2 at 7:00 AM, gradually climbing as the day unfolds. By 8:00 AM, it reaches 4, signaling an increase in sun exposure. As the sun ascends, the intensity soars, peaking at a remarkable 15 by noon. This is the time to take precautions! The afternoon sees a slight decline, with values tapering to 11 by 2:00 PM and then descending further to 7 at 3:00 PM. As evening approaches, the index drops swiftly, hitting 1 by 5:00 PM and fading to 0 by 7:00 PM, marking the end of a vibrant day under the sun. Don't forget to protect your skin during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 8 | very high | 15 min |
| 10:00 | 11 | extreme | 10 min |
| 11:00 | 14 | extreme | 10 min |
| 12:00 | 15 | extreme | 10 min |
| 13:00 | 14 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index data presents a notable trend of consistently high UV levels from January through November, classified as “extreme.” The month of March peaks with an index of 16, followed closely by April and July, while February is slightly higher at 14. Visitors and residents should be particularly vigilant during these high-risk months, as the burn time is a mere 10 minutes across most months, emphasizing the need for sun protection such as sunscreen, hats, and protective clothing when outdoors. As the year progresses into December, there is a slight reduction in UV exposure, decreasing to a very high level with a burn time of 15 minutes. It’s crucial for everyone to remain aware of the high UV index and take appropriate precautions year-round to safeguard against harmful sun exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Petapa UVI | 11 | 13 | 14 | 15 | 14 | 14 | 14 | 14 | 14 | 13 | 10 | 10 |
| Villa Nueva UVI | 11 | 13 | 14 | 15 | 14 | 14 | 14 | 14 | 14 | 13 | 10 | 10 |
| Mixco UVI | 11 | 13 | 15 | 15 | 14 | 14 | 14 | 14 | 14 | 13 | 11 | 10 |
| Guatemala City UVI | 11 | 13 | 15 | 15 | 14 | 14 | 14 | 14 | 14 | 13 | 11 | 10 |
| San Juan Sacatepequez UVI | 11 | 13 | 15 | 15 | 14 | 14 | 15 | 14 | 14 | 13 | 11 | 10 |
| San Marcos | 12 | 14 | 16 | 16 | 15 | 15 | 16 | 15 | 14 | 14 | 11 | 10 |