Last updated: August 1, 2025
Understanding the UV Index is crucial for residents and visitors of Bim Son, Vietnam, where the climate falls under the Cwa zone, characterized by humid summers and dry winters. With UV levels peaking to a startling 14 at noon, awareness of these fluctuations is essential to prevent sunburn and maintain skin health. By grasping the UV exposure risks throughout the day—such as intense peaks from 10:00 AM to 12:00 PM—you can take proactive measures to protect yourself against harmful rays, ensuring enjoyable outdoor experiences while safeguarding your skin.
The UV Index throughout the day shows a significant rise, peaking dramatically between 12:00 PM and 1:00 PM, when it reaches a maximum of 14. Early morning hours start off relatively mild, with a 2 at 7:00 AM, gradually climbing to 4 by 8:00 AM. As the sun rises higher, 9:00 AM sees a notable leap to 7, followed by an intense 10 at 10:00 AM. The 11:00 AM mark escalates to 13, making the midday sun a prime time for sun protection. After this peak, the index begins to decline, tapering to 12 at 1:00 PM, and descending through the afternoon to 6 by 3:00 PM. As evening approaches, the UV Index drops sharply, concluding at 0 by 7:00 PM. This data emphasizes the importance of UV awareness during peak hours.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 10 | very high | 15 min |
| 11:00 | 13 | extreme | 10 min |
| 12:00 | 14 | extreme | 10 min |
| 13:00 | 12 | 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 |
The UV Index experiences significant fluctuations throughout the year, with the highest levels occurring from March to October, where it consistently reaches the extreme category. The peak months are July, August, and September, where the UV Index soars to 14, resulting in a rapid burn time of just 10 minutes. Conversely, the months of January and February also manifest a very high exposure risk with an index of 8 and 10, respectively, maintaining a 15-minute burn time. To ensure safety, visitors and residents are strongly advised to take precautions during these high-risk months by wearing protective clothing, applying sunscreen, and seeking shade, especially during midday hours when UV exposure is greatest. In contrast, November and December, while still reflecting moderate UV levels, allow for longer exposure times with 15 to 25 minutes before burning occurs.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hanoi UVI | 8 | 10 | 12 | 12 | 13 | 12 | 12 | 13 | 13 | 11 | 9 | 7 |
| Haiphong UVI | 8 | 10 | 12 | 13 | 12 | 13 | 13 | 13 | 13 | 11 | 9 | 7 |
| Bim Son | 8 | 10 | 12 | 13 | 13 | 13 | 14 | 14 | 14 | 11 | 9 | 7 |
| Da Nang UVI | 10 | 12 | 14 | 15 | 14 | 13 | 14 | 14 | 13 | 12 | 10 | 9 |
| Ho Chi Minh City UVI | 10 | 13 | 15 | 14 | 14 | 12 | 13 | 14 | 13 | 13 | 11 | 10 |
| Bien Hoa UVI | 10 | 14 | 15 | 15 | 14 | 13 | 14 | 14 | 13 | 12 | 11 | 10 |