Last updated: June 2, 2025
In Columbia Falls, understanding the UV Index is vital for protecting your skin and overall health throughout the year. With a Dfb climate, residents experience varying UV levels that can lead to sunburn and long-term skin damage, especially during peak hours when the index reaches a high of 10 around noon. Awareness of these UV levels empowers you to take necessary precautions, such as wearing sunscreen and protective clothing, to enjoy the beautiful Montana outdoors while minimizing your risk of sun-related issues. Keep an eye on the UV Index to stay safe and have fun under the sun!
As the sun rises, the UV Index gradually increases, starting at a mild 2 at 07:00. By 08:00, it climbs to 3, indicating a need for some sun protection. However, the intensity of UV rays peaks at 12:00 and 13:00, reaching an impressive 10—a level that warrants serious caution. From there, the UV Index begins to decline, dropping to 8 by 14:00 and gradually tapering off to 5 by 16:00. Finally, as the day winds down, the index falls to 3 at 17:00 and settles at a minimal level of 1 by 18:00 and 19:00. It's clear that midday calls for the most vigilance against sun exposure, making protection essential during those peak hours.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 7 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index exhibits notable seasonal variations, with the highest levels occurring during the summer months. May and June stand out as the months with the highest risk, featuring very high UV Index values of 9 and 10, respectively, allowing for a burn time as short as 15 minutes. From April to August, the UV exposure is particularly concerning, with values of 7 or more, categorizing these months as high to very high risk for skin damage. Visitors and residents are strongly advised to take precautions during these months, such as wearing protective clothing, using broad-spectrum sunscreen, and seeking shade, especially during midday hours when UV radiation is at its peak. As we transition into fall and winter, the UV Index decreases, becoming low in January and December, providing a reprieve from intense sun exposure and longer burn times of 45 minutes.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Columbia Falls | 2 | 4 | 5 | 7 | 9 | 10 | 8 | 8 | 7 | 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 |