Last updated: June 2, 2025
Understanding the UV Index is crucial for anyone enjoying the sun-kissed beauty of Costa Rica and Peru. With the region's tropical climate, UV levels can rise dramatically, peaking at an alarming 11 from late morning to early afternoon. This makes awareness of UV exposure essential not just for preventing painful sunburns, but also for protecting long-term skin health. By monitoring the UV Index throughout the day, you can take proactive steps to safeguard yourself and your loved ones from the harmful effects of UV radiation, ensuring that your adventures in these stunning locales are both enjoyable and safe.
The UV Index begins its ascent at 07:00 with a low reading of 1, gradually rising to 2 by 08:00. As the day progresses, the intensity of UV radiation peaks at 12:00, hitting a maximum of 11—a critical level where sun protection is essential. Following this zenith, the index starts to decline, measuring 10 at 13:00, then tapering off to 8 by 14:00. By mid-afternoon, the UV Index drops to 5 at 15:00 and continues its downward trajectory, reaching 2 at 16:00. As the sun sets, the UV index decreases to 1 by 17:00 and ultimately settles at 0 by 18:00, signifying the end of significant UV exposure for the day. It's a reminder that while the sun's rays can be intense at midday, the morning and late afternoon offer safer conditions for outdoor activities.
| 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 | 8 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 8 | 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 |
Throughout the year, the UV Index remains extremely high, particularly from January to April, where it peaks at 16. These months are critical for residents and visitors to take precautionary measures, as the burn time is only 10 minutes during this period. Although the index slightly declines during the summer months, it still remains significantly high, with values of 11 to 12 from June to August. As the year progresses into the fall, the index again reaches up to 15 in October, before tapering off slightly in November and December. It is advisable for everyone to wear sunscreen, protective clothing, and seek shade during peak sun hours, especially during the high-risk months of January through April. Staying informed and vigilant about UV exposure can help minimize the risk of 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 |
| Costa Rica | 15 | 16 | 16 | 16 | 14 | 11 | 11 | 12 | 14 | 15 | 14 | 14 |
| Arequipa UVI | 18 | 17 | 17 | 15 | 12 | 10 | 11 | 13 | 15 | 17 | 18 | 17 |