Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of Ba To, Vietnam, where the tropical climate brings intense sunlight and varying UV exposure throughout the day. Recognizing UV levels is essential not only for preventing sunburn but also for protecting overall skin health in this vibrant region. With peak UV Index values soaring to 14 between 12:00 PM and 1:00 PM, it's important to be aware of the risks associated with high UV levels, especially during the sunniest hours, to enjoy the beautiful outdoor scenes in Ba To safely.
As the sun rises, the UV Index begins its ascent, starting at a mild 2 by 7:00 AM. By 8:00 AM, it ramps up to 4, signaling the need for light sun protection. The real intensity kicks in around 9:00 AM, peaking at a robust 11 between 10:00 AM and 12:00 PM, when it reaches its highest point of 14. During these hours, it’s essential to find shade and apply sunscreen to shield yourself from harmful rays. As the afternoon progresses, the UV Index gradually declines, dropping to 12 at 1:00 PM before easing to 6 by 3:00 PM, and finally dipping to a low of 1 by 5:00 PM, signaling a retreat from the sun as daylight fades. This data emphasizes the importance of midday sun safety, ensuring maximum protection during the peak UV exposure.
| 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 | 14 | 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 seasonal UV changes indicate that from January to April, the UV Index rises dramatically from 10 to 15, categorizing these months as having an extreme exposure risk with a burn time of just 10 minutes. The highest risk months are March, April, and May, where the UV Index consistently reaches 15. As summer approaches, the index remains high but slightly decreases to 13 in June and 14 in July and August, sustaining an extreme exposure category. In September, the risk remains intense at 14 but begins to taper off in October (12) and November (11), before declining to 9 in December, moving back to a very high exposure status with a burn time of 15 minutes. Visitors and residents are strongly advised to take protective measures during these high-risk months—especially from March through November—by wearing sunscreen, protective clothing, and seeking shade to minimize UV exposure.
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 |
| 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 |
| Ba To | 10 | 12 | 14 | 15 | 15 | 13 | 14 | 14 | 14 | 12 | 11 | 9 |
| Bien Hoa UVI | 10 | 14 | 15 | 15 | 14 | 13 | 14 | 14 | 13 | 12 | 11 | 10 |