Last updated: July 2, 2025
In Grass Lake, United States, being aware of the UV Index is crucial for protecting your skin and overall health. Understanding the daily UV levels can help you prevent sunburn and reduce the long-term risks of skin damage. With a Dfb climate, Grass Lake experiences varying UV exposure throughout the year, making it essential for residents and visitors alike to stay informed. During peak hours, such as between 11 AM and 2 PM, UV levels can soar to 10, indicating a high risk for harm. By keeping an eye on the UV Index, you can enjoy the outdoors safely while safeguarding your skin.
As the sun rises, the UV Index begins to climb, starting at a gentle 1 at 7:00 AM and remaining steady through 8:00 AM. By 9:00 AM, it nudges up to 2, but as the day progresses, the intensity skyrockets. At 10:00 AM, it hits 4, and by midday, the UV Index soars to a peak of 10 at both 1:00 PM and 2:00 PM—a clear indication to seek shade and wear sunscreen. After this peak, it gradually dips to 9 by 3:00 PM, continuing its descent to 5 at 5:00 PM, and finally, the UV levels soften to 1 as evening falls at 7:00 PM. This day exemplifies the sun's potent rays, reminding us to stay vigilant during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | 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 shows significant seasonal changes, impacting the risk of sun exposure. January and December have the lowest UV levels (2), indicating a low risk for sunburn, with burn times of 45 minutes. As spring unfolds, February and March present moderate UV levels (4-5) and shorter burn times of 30 minutes, signaling the need for increased sun protection. The high-risk months commence in April, peaking in June and July with very high UV Index values (9-10) and critical burn times of only 15 minutes; thus, it’s essential for visitors and residents to take protective measures, such as wearing sunscreen, hats, and UV-blocking clothing. August to September gradually sees a decline, but caution remains crucial with a high level of UV (7) in September and a burn time of 25 minutes. In October and November, UV levels moderate again to 4 and 5, respectively, where sun safety should continue to be a priority until levels drop back to low in December. Always consider the UV Index when planning outdoor activities, particularly during the peak summer months.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grass Lake | 2 | 4 | 5 | 9 | 9 | 10 | 10 | 9 | 7 | 5 | 4 | 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 |