Last updated: August 1, 2025
Understanding the UV Index is crucial for residents and visitors in San Juan, Bolivia, where the sun's rays can pose significant risks, especially during peak hours. With UV levels often soaring to 9 at noon, awareness of these fluctuations is vital for preventing sunburn and protecting your skin health. San Juan’s BSk climate features intense sunshine, making it essential to stay informed about UV exposure to enjoy the great outdoors safely. Stay vigilant and embrace sun safety practices to safeguard your skin from harmful UV radiation while relishing the striking Bolivian landscape.
As the sun rises, the UV Index starts off low, peaking at just 1 by 8 AM. However, as the day progresses, intensity increases, reaching a notable 6 by 10 AM and soaring to its maximum of 9 from noon to 1 PM. This peak signifies a time when sun safety becomes essential, urging you to seek shade and apply sunscreen. The afternoon sees a gradual decline with the index dropping to 5 by 3 PM and lower values as the sun begins its descent. By ~4 PM, the index falls to 2, and soon after, it returns to 1 by 5 PM, fading to 0 in the evening. Overall, it’s wise to take precautions during the midday hours when the UV levels are at their highest!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 7 | high | 25 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 6 | 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 |
Throughout the year, the UV Index displays significant seasonal variation, with extreme exposure levels from January to April and again in August, September, October, and November. Concerned especially high-risk months include January, February, March, April, August, October, and November, where the UV Index remains at 18 or higher, indicating a burn time of as little as 10 minutes. Conversely, during June and July, although classified as very high, the burn time increases to 15 minutes due to a slightly lower index of 8 or 9. Visitors and residents should take precautions during these high-risk months by applying broad-spectrum sunscreen, wearing protective clothing, and seeking shade, especially during peak sunlight hours, to minimize health risks associated with UV exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Santa Cruz de la Sierra UVI | 15 | 15 | 14 | 13 | 10 | 8 | 9 | 10 | 12 | 15 | 16 | 16 |
| Sucre UVI | 17 | 17 | 16 | 14 | 11 | 9 | 10 | 12 | 15 | 17 | 17 | 18 |
| San Juan | 18 | 18 | 16 | 14 | 11 | 8 | 9 | 12 | 14 | 17 | 18 | 18 |
| Sacaba UVI | 17 | 18 | 17 | 15 | 12 | 10 | 10 | 13 | 15 | 17 | 18 | 19 |
| Cochabamba UVI | 18 | 18 | 17 | 15 | 12 | 10 | 11 | 13 | 16 | 18 | 18 | 19 |
| Oruro UVI | 19 | 19 | 17 | 16 | 13 | 10 | 11 | 14 | 16 | 19 | 19 | 19 |