Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Merizo Village, Guam, where the tropical climate can lead to significant sun exposure. As UV levels can soar, especially during midday hours, being aware of these levels is essential for preventing sunburn and promoting long-term skin health. With UV Index readings peaking at a striking 14 around noon, it becomes evident that mindful sun protection is vital in this sun-soaked paradise. By grasping the potential risks associated with these elevated UV levels, you can enjoy the stunning outdoors while safeguarding your skin against harmful effects.
The UV Index for the day presents a dynamic shift in sun exposure, climbing steadily from a safe 1 at 07:00 to an impressive peak of 14 at 12:00. As the sun rises, so does the intensity of its rays, reaching a notable 12 at 11:00. Between 10:00 and 14:00, the UV Index remains high, urging caution—particularly at 11:00 and 12:00, when protective measures are essential. As the afternoon progresses, values gradually dip, descending to 8 at 15:00 and further to 2 by 17:00. By evening, the UV Index falls to 0 at 19:00, signaling a welcome retreat from the sun's harmful rays. Remember to stay sun savvy during peak hours for your skin’s health!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 12 | extreme | 10 min |
| 12:00 | 14 | extreme | 10 min |
| 13:00 | 13 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, the UV Index remains extremely high, particularly from January to September, where it consistently peaks at 15 in March, April, and September. This period signifies the highest risk for sunburn, with a burn time of just 10 minutes under direct sunlight. February and June also present significant risks, making these months particularly dangerous for unprotected skin. As we move into the fall and winter months, the UV Index begins to decrease but still maintains a high level of 12 in November and 11 in December. Visitors and residents are strongly advised to take precautions year-round, such as using broad-spectrum sunscreen, wearing protective clothing, and seeking shade during peak sunlight hours to minimize the risks associated with intense UV exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Barrigada Village UVI | 11 | 13 | 15 | 15 | 13 | 14 | 14 | 14 | 15 | 13 | 12 | 11 |
| Mangilao Village UVI | 11 | 13 | 15 | 15 | 13 | 14 | 14 | 14 | 15 | 13 | 12 | 11 |
| Tamuning-Tumon-Harmon Village UVI | 11 | 13 | 15 | 15 | 13 | 14 | 14 | 14 | 15 | 13 | 12 | 11 |
| Yigo Village UVI | 11 | 13 | 15 | 15 | 13 | 14 | 14 | 14 | 15 | 13 | 12 | 11 |
| Dededo Village UVI | 11 | 13 | 15 | 15 | 13 | 14 | 14 | 14 | 15 | 13 | 12 | 11 |
| Merizo Village | 11 | 13 | 15 | 15 | 13 | 14 | 14 | 14 | 15 | 14 | 12 | 11 |