Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of Grand Marais, where sun exposure can lead to serious skin health issues. With our Dfb climate bringing favorable summer conditions, it's easy to underestimate the risks associated with high UV levels, especially during peak hours when the index surges to 9 around midday. By keeping a close eye on the UV Index, you can take proactive steps to prevent sunburn and protect your skin, ensuring you enjoy the stunning outdoor activities this charming lakeside destination has to offer, without compromising your health. Remember, informed sun safety is key to making the most of sunny days in beautiful Grand Marais!
As the sun rises, the UV Index begins its gradual ascent. At 7:00 AM, it starts at a modest 1, indicating minimal risk. By 8:00 AM, it rises to 2, still manageable for early risers. The intensity picks up at 9:00 AM with a 3, signaling the need for a little sunscreen. The peak arrives between 11:00 AM and 1:00 PM, where it soars to a striking 9 at 1:00 PM, which suggests strong sun protection is essential. Following this, the index slips down, recorded at 8 at 2:00 PM and 7 at 3:00 PM, offering a brief reprieve. As the afternoon fades into evening, the UV Index drops steadily, landing back at 1 by 7:00 PM. Stay informed and protect your skin during those peak hours!
| 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 |
The UV Index varies significantly throughout the year, indicating fluctuations in sun exposure risks. January and November present low UV levels (index 2), with a burn time of 45 minutes. However, from February to April, the UV Index rises, reaching moderate levels (4 to 6) and decreasing burn times to 30 minutes and then 25 minutes. The high-risk months, characterized by a very high UV Index (8 to 9), occur from May through August, where the burn time shrinks significantly to just 15 minutes. September sees a slight reduction to a high category (index 7) with a burn time of 25 minutes before tapering off into moderate levels in October. Visitors and residents are strongly advised to take precautions during the high-risk months: wear protective clothing, apply broad-spectrum sunscreen regularly, and seek shade during peak sun hours to minimize skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grand Marais | 2 | 4 | 5 | 6 | 8 | 9 | 9 | 8 | 7 | 5 | 2 | 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 |