Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Thermopolis, United States, where the sun can shine brightly, especially in the warm summer months. With typical UV levels peaking around 11 during midday hours, it's essential for everyone to be aware of the risks associated with prolonged sun exposure, such as sunburn and long-term skin health issues. Thermopolis, nestled in a BWk climate zone, experiences significant UV exposure that can lead to increased risks if precautions aren't taken. Staying informed about the UV Index not only helps you enjoy the outdoors safely but also protects your skin from harmful effects.
At dawn, the UV Index starts off gentle, peaking at 1 by 7:00 AM. As the sun climbs higher, the index rises steadily, hitting 2 by 8:00 AM, then surging to 4 at 9:00 AM. The intensity escalates, reaching a robust 6 by 10:00 AM, and striking its peak at 10 by noon. The highest values occur between 1:00 PM and 2:00 PM, where it boldly stands at 11. As the afternoon progresses, the index begins to wane, falling to 9 at 3:00 PM, then dropping further to 7 by 4:00 PM. By 5:00 PM, the UV Index returns to a more manageable 4, before tapering off to 2 at 6:00 PM and concluding at 1 by 7:00 PM. It's essential to stay protected during those peak hours for safe sun exposure!
| 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 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, seasonal UV changes reflect a pattern of increasing intensity from winter to summer and a decline toward winter again. High-risk months occur from March to August, peaking in June and July when the UV Index reaches an extreme level of 11, with a burn time of just 10 minutes. During these months, residents and visitors should take extra precautions, such as seeking shade, wearing protective clothing, and applying sunscreen regularly, especially between 10 a.m. and 4 p.m. As the fall approaches, UV levels gradually decrease, but caution should still be exercised in September and early October when UV values remain elevated. Overall, ensuring proper skin protection is crucial during the high-risk periods to mitigate the dangers of UV exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago UVI | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| Brooklyn UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| New York City UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| Thermopolis | 3 | 5 | 6 | 9 | 10 | 11 | 11 | 10 | 9 | 6 | 4 | 3 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |