Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors in San Juan Chamelco, Guatemala, where the Cwb climate brings a unique blend of sunshine and altitude. Awareness of UV levels not only helps prevent painful sunburns but also plays a vital role in maintaining your skin's health over time. Between the hours of 10:00 AM and 2:00 PM, the UV Index can soar to dangerous levels, peaking at 14, which signifies an extreme risk for unprotected skin. With San Juan Chamelco's high elevation and tropical climate, recognizing these risks ensures you can enjoy the beautiful surroundings while keeping your skin safe.
The UV Index throughout the day displays a dramatic rise and fall, serving as a reminder to take sun safety precautions. Starting at 2 at 7:00 AM, the index quickly escalates, reaching 10 by 10:00 AM, peaking at an impressive 14 around 12:00 PM. This midday intensity signals the importance of protective measures against harmful rays. As the afternoon progresses, the index retreats, dropping to 7 by 3:00 PM and gently tapering off to 1 by 5:00 PM. By 7:00 PM, it sinks to 0, indicating a clear sky free from UV threat. Enjoy the sun, but remember 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 | 7 | high | 25 min |
| 10:00 | 10 | very high | 15 min |
| 11:00 | 13 | extreme | 10 min |
| 12:00 | 14 | extreme | 10 min |
| 13:00 | 13 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index experiences significant seasonal variation, peaking in the spring and summer months. January starts with a UV Index of 10 (very high), which increases sharply to 12 in February and reaches an extreme 14 by March. The highest levels occur from April to September, maintaining an extreme 14 throughout, with the UV Index only dipping slightly to 13 in September. October also remains in the extreme category at 12, before dropping back to very high levels of 10 in November and 9 in December. Given these values, the high-risk months for sun exposure are from March to October, and it is crucial for visitors and residents to take proactive measures during these times—limiting sun exposure to no more than 10 minutes during peak hours, wearing protective clothing, and applying broad-spectrum sunscreen to avoid harmful UV effects.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| San Juan Chamelco | 10 | 12 | 14 | 15 | 14 | 14 | 14 | 14 | 13 | 12 | 10 | 9 |
| 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 |