Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of San Francisco, Philippines, as it serves as a key indicator of how much ultraviolet radiation is present in the sunlight. With UV levels fluctuating throughout the day, being aware of these levels can significantly help in preventing sunburn and promoting long-term skin health. In the tropical climate of San Francisco, where UV Index readings can soar to as high as 13 during peak hours, the risk of overexposure is undeniable. Protecting yourself during these high-risk times ensures a safe and enjoyable experience under the sun.
The UV Index for the day reveals a clear peak in intensity between 10:00 AM and 1:00 PM, where values soar to a striking 13. Early risers will notice a modest 2 at 7:00 AM, gradually climbing to a moderate 4 by 8:00 AM. As the sun climbs higher, 9:00 AM sees a significant jump to 8, followed by an aggressive leap to 11 at 10:00 AM. The zenith is reached at 11:00 AM and 12:00 PM, both recording a 13, prompting caution for those outdoors. After this peak, the intensity starts to wane, dropping to 12 by 1:00 PM and continuing its descent to 5 by 3:00 PM. By 4:00 PM, the index falls to 2, indicating a much safer level for outdoor activities, and by evening, a 0 signifies that UV exposure is no longer a concern from 6:00 PM onward. Make sure to plan your day wisely around these UV fluctuations!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 8 | very high | 15 min |
| 10:00 | 11 | extreme | 10 min |
| 11:00 | 13 | extreme | 10 min |
| 12:00 | 13 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 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 consistently high, indicating extreme exposure risk for both visitors and residents. The months with the highest UV readings peak in March and April, each reaching a UV Index of 16, accompanied by a burn time of just 10 minutes. High-risk months extend from January to June, with UV levels staying above 13. Notably, September through November still maintain a UV Index of 12 to 14, emphasizing the persistent risk into the fall. It is crucial for everyone to apply broad-spectrum sunscreen, wear protective clothing, and seek shade during peak hours to mitigate the risks associated with prolonged sun exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Caloocan City UVI | 11 | 13 | 15 | 15 | 13 | 14 | 13 | 14 | 14 | 13 | 10 | 10 |
| Quezon City UVI | 11 | 13 | 15 | 15 | 13 | 14 | 13 | 14 | 14 | 13 | 10 | 10 |
| Manila UVI | 11 | 13 | 14 | 14 | 13 | 13 | 13 | 14 | 14 | 13 | 10 | 10 |
| San Francisco | 13 | 14 | 16 | 16 | 14 | 13 | 13 | 14 | 14 | 14 | 12 | 11 |
| Budta UVI | 13 | 15 | 16 | 16 | 14 | 13 | 14 | 14 | 15 | 14 | 13 | 11 |
| Davao UVI | 13 | 15 | 16 | 15 | 15 | 13 | 14 | 14 | 15 | 14 | 13 | 11 |