Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of Butte, United States, as it provides valuable insights into potential sun exposure hazards. With high UV levels peaking at 10 during midday, being aware of these numbers can help prevent sunburn and safeguard your skin health. Butte's humid continental climate presents specific challenges, with significant UV exposure risks, especially in the summer months. Whether you're enjoying outdoor activities or simply soaking up the sun, knowing the UV Index can empower you to take necessary precautions for a healthier, safer experience outdoors.
As the sun rises, the UV Index begins its steady ascent, starting at a mild 1 at 7:00 AM. By 8:00 AM, it reaches 2, hinting at the day ahead. As we approach mid-morning, the intensity climbs to 3 by 9:00 AM and then dramatically spikes to 5 at 10:00 AM. The real peak occurs between 12:00 PM and 2:00 PM, where the index soars to a whopping 10, indicating strong sun exposure. This midday intensity begins to taper off by 3:00 PM, as it drops to 9, and continues to slide through the late afternoon, ending the day at 1 by 7:00 PM. It's crucial to stay protected during those peak hours to enjoy the sun safely!
| 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 | 7 | high | 25 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 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
The UV Index varies significantly throughout the year, with high-risk months typically observed from March to September. During this period, the UV Index peaks in June at an extreme level of 11, necessitating protected exposure of only 10 minutes to prevent skin damage. April and May both present very high indices of 9 and 10, respectively, with burn times decreasing to 15 minutes. It is crucial for visitors and residents to take precautions during these months by wearing sunscreen, protective clothing, and sunglasses, especially from noon to 4 PM when the sun's rays are strongest. In contrast, the UV Index is much lower in January and December, ranging from 2 to 3, allowing for safer outdoor activities with longer burn times of 30 to 45 minutes. Therefore, awareness and proactive measures are essential throughout the peak UV months to ensure skin health and safety.
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 |
| Butte | 3 | 4 | 7 | 9 | 10 | 11 | 10 | 10 | 8 | 5 | 4 | 2 |
| 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 |