Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Sao Hai, Thailand, where the tropical climate brings about significant sun exposure. The UV levels vary throughout the day, peaking at a high of 13 around noon, emphasizing the importance of protecting your skin from harmful rays. Awareness of these levels not only helps prevent painful sunburns, but also plays a vital role in maintaining long-term skin health. With the potential for intense UV radiation, especially during the hottest hours, knowing when to seek shade or apply sunscreen can make all the difference in ensuring your outdoor activities remain safe and enjoyable.
At 07:00, the UV Index starts at a low 1, providing a gentle introduction to the day. As the sun climbs higher, the intensity begins to rise sharply, hitting 3 by 08:00 and reaching a notable 5 by 09:00. The real surge occurs between 10:00 and 12:00, where the UV Index soars from 9 to a peak of 13. The afternoon maintains this intensity, with 12 at 13:00 and gradually tapering off afterward. By 15:00, it dips to 7, then drops further to 4 by 16:00. As the sun sets, the UV Index returns to a lower level, sitting at 2 by 17:00, and finally tapering to 1 at 18:00, before completely fading to 0 by 19:00. This daily UV Index cycle highlights the importance of sun safety during peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 12 | extreme | 10 min |
| 12:00 | 13 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index exhibits significant variability throughout the year, with particularly high levels from February to October. This period is characterized by an extreme exposure category, peaking in April with an index of 14. March through October consistently shows an index of 12-13, indicating a dangerous risk of harm from unprotected sun exposure, with a minimal burn time of just 10 minutes. The high-risk months are notably February, March, April, May, June, July, August, September, and October, where it is crucial for visitors and residents to take precautions. During these months, it’s advisable to wear protective clothing, apply broad-spectrum sunscreen, and seek shade during peak hours to minimize the risk of skin damage. In contrast, January, November, and December have a lower UV Index, falling under the very high category, allowing for slightly longer exposure times of 15 minutes without protection. However, caution is still recommended during these months as well.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sao Hai | 9 | 12 | 13 | 14 | 13 | 12 | 13 | 13 | 13 | 12 | 10 | 9 |
| Mueang Nonthaburi UVI | 10 | 12 | 14 | 13 | 14 | 13 | 14 | 14 | 13 | 12 | 9 | 8 |
| Samut Prakan UVI | 10 | 12 | 14 | 13 | 14 | 13 | 14 | 14 | 13 | 12 | 9 | 8 |
| Bangkok UVI | 10 | 12 | 14 | 13 | 14 | 13 | 14 | 14 | 13 | 12 | 9 | 8 |
| Udon Thani UVI | 9 | 11 | 13 | 14 | 14 | 13 | 14 | 14 | 14 | 12 | 10 | 9 |
| Chon Buri UVI | 10 | 13 | 14 | 14 | 14 | 13 | 14 | 14 | 13 | 13 | 10 | 9 |