Last updated: June 2, 2025
Understanding the UV Index in Duluth, United States is essential for protecting your skin and overall health. As UV levels climb throughout the day, awareness becomes key in preventing sunburn and long-term skin damage. With a Dfb climate that features warm summers and cold winters, Duluthians should be particularly mindful of midday sun exposure, when UV levels peak at a risk-rated 9. By keeping an eye on the UV Index, you can enjoy the outdoors safely while minimizing harmful effects from the sun.
As the day dawns, the UV Index begins its ascent, starting at a gentle 1 by 7:00 AM. By 9:00 AM, it noticeably climbs to 4, signaling a more moderate level of sun exposure. The sun reaches its zenith at 12:00 PM, peaking at a robust 9, where precautions become essential. This level remains steady until 2:00 PM, encouraging outdoor enthusiasts to stay sun-safe. As the afternoon wanes, the UV index gradually declines, dipping to 6 by 4:00 PM, before settling back down to 1 by 7:00 PM. Early risers can begin enjoying the outdoors as conditions remain more forgiving in the morning, but midday calls for vigilance to protect your skin from the sun’s strongest rays.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 9 | 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, UV Index levels reflect significant seasonal changes that impact sun safety for residents and visitors. January and December feature low UV levels (2), with a safe burn time of 45 minutes, ideal for outdoor activities. As spring approaches, February and March see moderate UV levels (3 and 4) and reduced burn times of 30 minutes, prompting increased caution. The risk escalates dramatically from April through August, peaking in June and July with very high levels (9) and a burn time of just 15 minutes. During these months, sun protection is crucial, especially for those outdoors for extended periods. September sees a slight decline to a high level (7) with a burn time of 25 minutes before returning to moderate levels (5 and 3) in October and November. Visitors and residents are encouraged to remain vigilant and use appropriate sun protection measures during high-risk months, particularly from April to August.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Duluth | 2 | 3 | 4 | 7 | 8 | 9 | 9 | 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 |