Last updated: August 1, 2025
Understanding the UV Index is crucial for residents and visitors of Long Thanh, Vietnam, as it highlights the intensity of ultraviolet radiation from the sun. Being aware of UV levels helps prevent sunburn and protects skin health, especially in a region where typical exposure risks can soar due to its Aw climate zone. During the peak hours from 10 AM to 1 PM, the UV Index can reach dangerously high levels, peaking at 13—a reminder to take precautions against harmful rays. By staying informed about the UV Index, you can enjoy the vibrant outdoor lifestyle of Long Thanh while safeguarding your skin from sun damage.
The UV Index fluctuates significantly throughout the day, peaking at 13 during the late morning and early afternoon hours. Starting out gently at 1 at 07:00, the index rises steadily, reaching 4 by 08:00, and then surging to a striking 10 by 10:00. The sun’s intensity continues to climb, hitting its maximum values of 13 at both 11:00 and 12:00. As the day progresses, the UV levels begin to taper off, dropping to 12 at 13:00, and then rolling down to 9 by 14:00. In the afternoon, the index decreases further, settling at 5 at 15:00 before dwindling to 3 at 16:00. The evening sees a sharp decline, with values falling back to 1 by 17:00 and then retreating to 0 after sunset. This hourly data underscores the importance of sun protection during peak UV times, especially from late morning to early afternoon.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 11 | extreme | 10 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 | 5 | moderate | 30 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 exhibits significant fluctuations, with notably high levels during the winter and spring months. January and December demonstrate a very high UV Index of 10, with a burn time of 15 minutes. However, February through November are classified as extreme exposure months, peaking at 15 in March and maintaining an index of 13-14 from February to August. The high-risk months include February to August, where a burn time drops to just 10 minutes across the board. Visitors and residents are advised to take extra precautions during these peak months by wearing protective clothing, applying sunscreen regularly, and seeking shade when outdoors to minimize the risk of UV-related harm.
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 |
| Long Thanh | 10 | 13 | 15 | 14 | 14 | 12 | 13 | 14 | 13 | 13 | 11 | 10 |
| 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 |