Last updated: May 3, 2025
Understanding the UV Index is vital for residents of Butte, United States, as it serves as a crucial indicator of sun exposure and associated health risks. With increasing UV levels peaking at 9 during mid-afternoon, it's essential to recognize the importance of monitoring these levels to prevent sunburn and promote skin health. Butte's typically dry Dfa climate exposes locals to significant UV radiation, making awareness even more critical. By staying informed about the UV Index, you can take proactive measures to enjoy the outdoors safely while safeguarding your skin.
Starting from 07:00 AM, the UV Index remains low at 1, perfect for a morning stroll. As the sun climbs higher, the intensity gradually increases: reaching 3 by 09:00 AM and then escalating to 4 at 10:00 AM. The peak intensity occurs at 01:00 PM, with a striking UV Index of 9, suggesting it's vital to seek shade or apply sunscreen during this hour. The afternoon sees a slight decline, with values of 8 at 03:00 PM and 6 by 04:00 PM. As the day winds down, the UV Index drops back to 4 at 05:00 PM, and then gently falls to 2 by 06:00 PM, before settling back at 1 near sunset. It's a day to stay sun-smart!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index exhibits notable seasonal fluctuations, peaking during the summer months. From January to April, the index gradually rises from 3 to 8, indicating a shift from moderate to very high risk. The risk of harm significantly increases in May and reaches its zenith in June with an extreme index of 11. High-risk months include March (UV Index 6) and April (UV Index 8), transitioning to very high risks from May through September when the index remains above 8. During these peak months, particularly in June, visitors and residents are strongly advised to take precautions: seek shade, wear protective clothing, and apply sunscreen regularly to mitigate skin damage. As the year progresses towards October and November, the UV Index decreases, returning to moderate levels by December, where exposure risks are lower and burn time increases to 45 minutes. This seasonal insight highlights the importance of adjusting sun safety practices throughout the year.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Butte | 3 | 5 | 6 | 8 | 9 | 11 | 10 | 10 | 8 | 5 | 3 | 2 |
| 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 |
| 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 |