Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Ulan Bator, Mongolia, where the thin atmosphere and high elevation lead to increased sun exposure. Being aware of the UV levels can significantly aid in preventing sunburn and protecting long-term skin health, especially during the summer months when values peak at a high of 9 around midday. Given Ulan Bator's BSk climate, which features sunny days and chilly evenings, it's essential to stay informed about UV risks from mid-morning to early afternoon, when activity outdoors can put you at greater risk. Prioritizing UV awareness allows you to enjoy the sun safely while taking advantage of the vibrant outdoor life Ulan Bator has to offer.
The UV Index reveals a dynamic day of sun exposure, starting with a gentle 1 at 07:00 and gradually ramping up as the morning unfolds. By 09:00, it climbs to 4, reaching a more noteworthy 6 at 10:00. As the sun reaches its zenith, the UV Index peaks at 9 during the crucial hours of 12:00 and 13:00, indicating a high risk of harm from unprotected sun exposure. The intensity begins to wane after 14:00, settling to 7 at 15:00 before gradually decreasing to 1 by 19:00. Remember to protect your skin between 11:00 and 14:00 when the sun’s rays are at their most dangerous!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 6 | high | 25 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index experiences significant seasonal fluctuations, with high-risk months identified as May through August, when the UV Index reaches a peak of 9, categorizing it as very high and resulting in a burn time of just 15 minutes. As the year progresses, the UV exposure starts low in January (Index 2) and gradually increases, peaking during the summer months before tapering off. Visitors and residents are advised to take extra precautions during the high-risk months by wearing protective clothing, applying broad-spectrum sunscreen frequently, and seeking shade, especially during midday hours. Starting in September, the risk decreases but remains moderately high, so vigilance is still necessary until the UV Index drops further in late autumn and winter.
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 | 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 |