Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in San Juan, Peru, where the climate often leans towards the BWk category, bringing with it unique sun exposure challenges. With peak UV levels reaching a high of 13 around noon, awareness of these levels is essential for preventing sunburn and maintaining overall skin health. The sun's intensity in San Juan means that even short periods of exposure can lead to harmful effects, making it vital to know when to seek shade and apply sunscreen. Monitoring the UV Index helps you protect your skin and enjoy the beautiful outdoor moments that this vibrant area has to offer!
As the sun rises, the UV Index begins at a low 1 at 07:00, gradually climbing to reach 2 by 08:00. The intensity ramps up significantly as the day progresses, peaking at a striking 13 at 12:00. The sun's rays hit their maximum power between 11:00 and 13:00, with a 12 at 11:00 and lingering at 13 until 12:00. After that, the UV Index starts to decline, dipping to 9 by 14:00 and further down to 5 by 15:00. As evening approaches, the index falls to 2 at 16:00, then returns to a safe 1 at 17:00 before wrapping up the day with a zero reading by 18:00. This pattern underscores the importance of sun safety during those peak hours when the UV Index is highest.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 12 | extreme | 10 min |
| 12:00 | 13 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 5 | moderate | 30 min |
| 16:00 | 2 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 0 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index data reveals extremely high levels of ultraviolet radiation throughout the entire year, with consistently high values between 14 and 19 from January to November. Notably, the highest risk months for UV exposure are from January to April, where the UV Index peaks at 19 in February and remains over 17 through April. May through September still maintain high levels, but are slightly lower, ranging from 11 to 16. Finally, October to December return to extreme levels at 18. Visitors and residents are strongly advised to take precautions, such as wearing protective clothing, applying broad-spectrum sunscreen, and seeking shade, especially during daytime hours when UV exposure is at its highest to prevent sunburn and long-term skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Callao UVI | 14 | 14 | 14 | 12 | 10 | 9 | 10 | 11 | 12 | 13 | 14 | 13 |
| Lima UVI | 14 | 14 | 14 | 12 | 10 | 9 | 10 | 11 | 12 | 13 | 14 | 13 |
| Trujillo UVI | 15 | 15 | 15 | 14 | 12 | 11 | 11 | 11 | 13 | 14 | 14 | 14 |
| Chiclayo UVI | 14 | 15 | 15 | 14 | 13 | 11 | 11 | 12 | 15 | 14 | 14 | 13 |
| Arequipa UVI | 18 | 17 | 17 | 15 | 12 | 10 | 11 | 13 | 15 | 17 | 18 | 17 |
| San Juan | 18 | 19 | 18 | 17 | 14 | 11 | 13 | 14 | 16 | 18 | 18 | 18 |