Last updated: June 2, 2025
Understanding the UV Index is crucial for the residents of Bayansayr, Mongolia, where the unique BSk climate comes with both the beauty of sunny days and the hidden risks of high UV exposure. As the sun rises, so does the potential for skin damage—particularly significant during peak hours around noon and early afternoon when the UV Index reaches levels of 9 and 10, indicating a very high risk of harm from unprotected sun exposure. By being aware of these UV levels, you can better protect yourself against sunburn and long-term skin health issues, ensuring that every outdoor adventure can be enjoyed safely.
At dawn, the UV Index begins its climb, starting at a mild 1 at 07:00. As the sun rises higher, it steadily ascends, reaching 2 by 08:00 and escalating to 3 by 09:00. The peak of the day arrives at noon with a striking 9, just before it hits its maximum of 10 from 13:00 to 14:00, signifying a need for sun protection. The intensity begins to taper off after that, dropping to 9 at 15:00, then descending through 7 at 16:00, and winding down to 4 by 17:00. As evening approaches, the UV Index dwindles to 3 by 18:00 and finally returns to 1 by 19:00, illustrating the clear and powerful influence of the sun throughout the day.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV exposure varies significantly, with a noticeable increase from March to August. The high-risk months are April to August, where the UV Index reaches 8-10, categorized as very high; during this period, the recommended burn time decreases to just 15 minutes. In contrast, January and December exhibit low exposure levels, with a UV Index of 2 and a burn time of 45 minutes. Visitors and residents should take extra precautions during the high UV months by wearing sunscreen, protective clothing, and seeking shade, especially between 10 AM and 4 PM when the sun's rays are the strongest. During the rest of the year, while the risk is lower, it is still advisable to be mindful of UV exposure, especially in March, September, and October with moderate UV levels.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Darhan UVI | 1 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 6 | 4 | 2 | 1 |
| Erdenet UVI | 2 | 3 | 5 | 7 | 8 | 9 | 9 | 8 | 6 | 4 | 2 | 1 |
| Ulan Bator UVI | 2 | 3 | 5 | 7 | 9 | 9 | 9 | 9 | 6 | 4 | 3 | 1 |
| OElgii UVI | 2 | 3 | 5 | 7 | 10 | 9 | 9 | 9 | 7 | 5 | 2 | 1 |
| Khovd UVI | 2 | 3 | 6 | 7 | 10 | 10 | 9 | 9 | 7 | 5 | 2 | 1 |
| Bayansayr | 2 | 3 | 6 | 8 | 10 | 10 | 10 | 10 | 7 | 5 | 3 | 2 |