Last updated: May 3, 2025
Understanding the UV Index is essential for residents and visitors in San Isidro, Peru, where the typical climate promotes high sun exposure. This metric helps you stay informed about harmful ultraviolet (UV) radiation levels, crucial for preventing sunburn and maintaining long-term skin health. With peak UV levels reaching a striking 13 around midday, it's vital to take precautions during the hottest hours. By being aware of the UV Index in this vibrant coastal city, you can enjoy the sun safely while minimizing potential risks associated with excessive sun exposure.
Starting at 7:00 AM, the UV Index is a mild 1, gradually rising as the sun climbs in the sky. By 8:00 AM, it reaches 4, making it a good time for sun protection. The intensity peaks sharply at 10:00 AM with a maximum index of 10, continuing to hold strong at 13 during the midday hours of 11:00 AM and 12:00 PM. This is the critical window when sun exposure can cause harm, so seek shade or wear protective gear if you're outside! As the afternoon progresses, the index begins to dip: it drops to 11 at 1:00 PM, then to 8 by 2:00 PM, before further declining to 4 at 3:00 PM. By 4:00 PM, it decreases to 2, prompting a cautious approach to the sun. Finally, as the day winds down, the index falls to 1 by 5:00 PM, and eventually drops to 0 after 6:00 PM, signaling that it's safe to enjoy the evening outdoors without worries about UV exposure.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | 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 | 13 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 4 | 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 |
Throughout the year, UV Index levels remain alarmingly high, particularly from January through April, where the index peaks at 17 in March, categorizing the risk of harm from unprotected sun exposure as extreme with a burn time of just 10 minutes. The high-risk months for UV exposure are undeniably the first four months of the year, demanding heightened caution from visitors and residents alike. As the year progresses into May through July, the UV Index gradually decreases but maintains an extreme rating, emphasizing the need for sun protection during outdoor activities. Even in the later months, from August to November, the UV Index remains elevated, never dropping below 12, signaling that vigilance is essential year-round. Residents and visitors should apply sunscreen generously, wear protective clothing, and seek shade during peak sun hours to safeguard their health against harmful UV radiation.
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 |
| San Isidro | 15 | 16 | 17 | 16 | 13 | 12 | 11 | 12 | 14 | 14 | 13 | 13 |
| Arequipa UVI | 18 | 17 | 17 | 15 | 12 | 10 | 11 | 13 | 15 | 17 | 18 | 17 |