Last updated: July 2, 2025
In Three Forks, Montana, understanding the UV Index is crucial for maintaining skin health and preventing sunburn. With a semi-arid climate that allows for intense sun exposure, residents and visitors should be particularly aware of the potential risks throughout the day. As UV levels peak at 10 around midday, it’s essential to protect your skin from harmful rays, especially during the warmer months when the sun's intensity increases. By staying informed about the UV Index, you can enjoy outdoor activities while keeping your skin safe and healthy!
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 |
Throughout the year, the UV Index exhibits notable seasonal variations, with high-risk months primarily occurring from March to September. During this period, particularly in June with an extreme UV Index of 11 and April to August, which consistently sees values between 8 and 10, individuals are at increased risk of sunburn with burn times decreasing to as little as 10 minutes. Conversely, the winter months of December and January reflect a lower UV Index, ranging from 2 to 3, providing a safer environment for sun exposure with burn times extending up to 45 minutes. It is advisable for visitors and residents to take protective measures during the high-risk months, including wearing sunscreen, protective clothing, and seeking shade, especially during peak sun hours.
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 |
| Three Forks | 3 | 5 | 6 | 8 | 9 | 11 | 10 | 9 | 8 | 5 | 3 | 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 |