Last updated: June 2, 2025
In Butte, United States, staying informed about the UV Index is crucial for maintaining skin health and preventing sunburns. The UV Index provides vital information about the intensity of ultraviolet radiation, helping residents and visitors alike make informed decisions about sun exposure. With Butte's Dfc climate, characterized by cool summers and varied UV exposure throughout the day, understanding these levels is essential to safeguard against the harmful effects of the sun. Be proactive in protecting your skin; knowing when the UV Index peaks, particularly between 11:00 AM and 2:00 PM, can make all the difference in enjoying the great outdoors safely!
Throughout the day, the UV Index experiences a notable rise, peaking during the early afternoon. Starting from a mild 1 at 7:00 AM, it gradually escalates, reaching a moderate 2 by 9:00 AM. The intensity grows rapidly, hitting 4 by 11:00 AM, and then surging to its maximum of 6 between 1:00 PM and 2:00 PM. As the afternoon progresses, the UV Index starts to decline, dropping to 4 by 5:00 PM and tapering off to a comfortable 2 by 7:00 PM. For outdoor enthusiasts, it's essential to protect your skin, especially when the index is elevated; the highest risk is present from noon to 2 PM. Stay safe and enjoy the sun!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 3 | moderate | 30 min |
| 11:00 | 4 | moderate | 30 min |
| 12:00 | 5 | moderate | 30 min |
| 13:00 | 6 | high | 25 min |
| 14:00 | 6 | high | 25 min |
| 15:00 | 5 | moderate | 30 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 2 | low | 45 min |
Throughout the year, seasonal UV changes indicate varying levels of sun exposure risk. From January to February, the UV Index remains low (1), allowing for a safe exposure time of up to 45 minutes. As we transition into March, the index rises to 3, indicating a moderate risk, reducing the safe exposure time to 30 minutes. The risk peaks in May through July with high UV levels (6 and 7), necessitating an exposure limit of just 25 minutes. In August and September, the index returns to moderate levels (5 and 4), allowing for a 30-minute burn time again. As the year concludes, October through December sees a return to low UV levels (1-2), with a safe exposure limit of 45 minutes. Residents and visitors should be particularly cautious during the high-risk months of May, June, and July, applying sunscreen and seeking shade to mitigate potential sun damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Butte | 1 | 1 | 3 | 4 | 6 | 6 | 7 | 5 | 4 | 2 | 1 | 1 |
| 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 |