Last updated: May 3, 2025
Understanding the UV Index in Nantucket, United States, is vital for maintaining skin health and preventing sunburn, especially during the summer months when UV exposure can reach dangerous levels. With peak UV readings soaring to 9 between noon and 1 PM, the risks associated with prolonged sun exposure are significant. In this charming coastal town, characterized by its Cfa climate, residents and visitors alike should be vigilant about understanding UV levels to ensure safe outdoor enjoyment. By staying informed about the daily UV Index, you can take proactive steps to protect your skin and embrace the beauty of Nantucket safely.
The UV Index for the day reveals an intensifying sun, peaking between 12:00 PM and 1:00 PM with a striking value of 9. Early in the day, at 7:00 AM, the index starts low at 1, allowing a gradual increase to 2 by 8:00 AM. As the hours progress, the UV exposure rises sharply, hitting 6 by 10:00 AM, and climbing to its maximum of 8 at 11:00 AM before reaching its zenith. After this midday spike, a gentle decline begins; the levels drop back to 8 at 2:00 PM, then 6 at 3:00 PM, and further decrease to 2 by 5:00 PM. The sun sets on the day’s UV journey with lingering low values of 1 for the last few hours. It's a reminder to stay protected during those peak hours!
| 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 | 8 | very high | 15 min |
| 15:00 | 6 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences notable fluctuations, with the highest risk months occurring from March to September, when the index consistently ranges between 6 and 10. Specifically, April to August feature very high levels, with peak values reaching 10 in June and July, corresponding to a dangerously short burn time of 15 minutes. In contrast, January and December present lower UV risks, categorized as moderate to low, with corresponding burn times of 30 minutes and 45 minutes, respectively. To safeguard your skin, it is crucial for visitors and residents to adopt protective measures, especially during the peak months by using sunscreen, wearing protective clothing, and seeking shade during midday hours to reduce UV exposure effectively.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nantucket | 3 | 5 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 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 |