Last updated: August 1, 2025
Understanding the UV Index is crucial for residents of Colby, United States, where varying exposure levels can greatly influence skin health and sunburn prevention. On sunny days, especially between 11:00 AM and 2:00 PM, the UV Index peaks at a significant level of 9, indicating a high risk of harm from unprotected sun exposure. With a Dfb climate, Colby experiences distinct seasons that can lead to fluctuating UV radiation, making it essential for locals to stay informed about daily UV levels. By understanding these metrics, you can better protect your skin and enjoy the outdoors safely all year round.
The UV Index throughout the day tells a compelling story of sun exposure. Starting at a gentle 1 at 7:00 AM, it gradually rises, reaching 2 by 8:00 AM. As the clock ticks towards mid-morning, the intensity ramps up, peaking at 9 between 12:00 PM and 2:00 PM—the perfect time for a shaded respite or sunscreen application. By 11:00 AM, the index hits 7, signaling more significant sun intensity. As the afternoon wanes, it starts to dip, falling to 3 by 5:00 PM, and eventually returning to 1 by 7:00 PM. This data emphasizes the importance of sun protection, particularly during those peak hours, to ensure a safe and enjoyable day outdoors!
| 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 | 8 | very high | 15 min |
| 13:00 | 9 | 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 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV Index levels fluctuate significantly, indicating varying risks of skin damage from sun exposure. The low-risk months are January and December, with UV Index levels of 2, allowing for about 45 minutes of safe sun exposure. As we move into early spring, February and March show a moderate index of 4 and 5, respectively, reducing burn time to 30 minutes. The high-risk months notably occur from April to August, peaking in June with a UV Index of 10, and requiring sunscreen application and minimal exposure after just 15 minutes. September dips to a high level of 7, while October and November present a moderate risk. Visitors and residents should take precautions, particularly during peak summer months by seeking shade, wearing protective clothing, and using sunscreen to minimize skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Colby | 2 | 4 | 5 | 7 | 8 | 10 | 9 | 9 | 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 |