Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Southwest Harbor, United States, especially during the summer months when sun exposure can lead to serious skin health issues, including painful sunburns. The UV Index serves as a vital tool in helping individuals gauge the sun's intensity throughout the day, ensuring they take appropriate precautions. With a Dfb climate known for its warm summers and moderate UV exposure risks, awareness of peak UV levels—often reaching a maximum of 10 around midday—can empower you to enjoy the outdoors safely. By recognizing these fluctuations, you can protect your skin, embrace the beauty of Southwest Harbor, and fully enjoy all its natural offerings!
The UV Index throughout the day reveals a clear progression of intensity, peaking during the midday hours. At 07:00, the index starts modestly at 2, but it swiftly climbs to reach 3 by 08:00. By 09:00, the sun's rays intensify further, hitting 5, and 10:00 sees it escalate to 7. The real surge happens as the clock strikes 11:00, where it peaks at 8, and then rockets to an impressive 10 by 12:00, maintaining this high level through 13:00. As the afternoon sets in, the index begins to decline slightly, dropping to 9 at 14:00 and tapering down to 7 by 15:00. As the day winds down, it further decreases to 5 at 16:00, 3 at 17:00, and eases into the evening with a low 1 by 18:00 and 19:00. This data vividly illustrates the importance of sun safety during peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 7 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index exhibits notable seasonal variations, with the highest levels occurring during the summer months. May and June stand out as the months with the highest risk, featuring very high UV Index values of 9 and 10, respectively, allowing for a burn time as short as 15 minutes. From April to August, the UV exposure is particularly concerning, with values of 7 or more, categorizing these months as high to very high risk for skin damage. Visitors and residents are strongly advised to take precautions during these months, such as wearing protective clothing, using broad-spectrum sunscreen, and seeking shade, especially during midday hours when UV radiation is at its peak. As we transition into fall and winter, the UV Index decreases, becoming low in January and December, providing a reprieve from intense sun exposure and longer burn times of 45 minutes.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Southwest Harbor | 2 | 4 | 5 | 7 | 9 | 10 | 8 | 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 |