Last updated: July 2, 2025
Understanding the UV Index is crucial for those living in Herlen, Mongolia, where the high-altitude climate can lead to significant sun exposure risks. Awareness of the UV levels not only helps in preventing painful sunburns but is also vital for maintaining overall skin health. With the UV Index peaking at a notable 9 during midday hours, residents must be mindful of their time outdoors, especially in the dry Dwc climate that intensifies UV radiation. By staying informed about the UV Index, you can better protect yourself and your loved ones from harmful effects of the sun.
As the sun rises, the UV Index begins its journey, peaking at 9 between 12:00 PM and 2:00 PM, indicating a strong risk of harm from unprotected sun exposure. Early in the morning, at 7:00 AM, the index starts low at only 1, making it safer for outdoor activities. By 9:00 AM, it increases to a moderate 4, prompting some sun safety precautions. The intensity intensifies, hitting 8 by 11:00 AM and 6 at 10:00 AM, urging those out and about to seek shade. As the afternoon progresses, the UV Index begins to taper off, decreasing to 7 at 3:00 PM, and down to 5 at 4:00 PM, signifying a safer end to the day. By 5:00 PM, it drops to 3, and by sunset at 7:00 PM, it returns to a minimal 1. Stay vigilant and protect your skin during the peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | 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 |
Throughout the year, UV Index values exhibit notable seasonal changes, significantly affecting sun exposure safety for both visitors and residents. The highest risk months for UV exposure are from May through August, where the Index peaks at a very high level of 9, indicating a burn time of just 15 minutes during peak sunlight hours. April marks the transition to higher risk with a high UV Index of 7, and as we move into September, the risk lowers to high at 6, allowing for a longer burn time of 25 minutes. In contrast, the winter months of January, November, and December present much lower risk levels, with UV Index values ranging from 1 to 2 and burn times of up to 45 minutes. Accordingly, it is crucial for everyone to take appropriate sun protection measures, especially during the high-risk months, such as wearing sunscreen, protective clothing, and seeking shade during peak hours.
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 |
| Herlen | 2 | 3 | 5 | 7 | 9 | 9 | 9 | 9 | 6 | 4 | 2 | 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 |