UV Index in Nantucket, United States

Last updated: June 2, 2025

Understanding the UV Index is crucial for residents and visitors of Nantucket, where sun exposure can significantly impact skin health. High UV levels, particularly during peak hours—reaching a maximum of 10 at noon—underscore the importance of sunburn prevention strategies. As this charming island experiences a temperate Cfa climate, awareness of UV risks not only helps protect against immediate skin damage but also reduces the risk of long-term health issues. Stay informed to enjoy Nantucket’s sun-filled days while safeguarding your skin!

Hourly UV Index in Nantucket

As the sun rises, the UV Index begins at a low 1 at 7:00 AM, gradually climbing as the day unfolds. By 8:00 AM, it reaches 3, signaling a mild increase in UV exposure. The intensity peaks between 12:00 PM and 1:00 PM, with the index hitting a maximum of 10, indicating a high risk of harm from unprotected sun exposure. Thankfully, the afternoon brings a decrease, with values declining to 7 at 3:00 PM and dropping further to 1 by 7:00 PM, as the sun sets. This data emphasizes the importance of sun protection during the midday hours when exposure is at its highest.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
TimeUVICategoryTime to Burn
07:001low45 min
08:003moderate30 min
09:004moderate30 min
10:007high25 min
11:009very high15 min
12:0010very high15 min
13:0010very high15 min
14:009very high15 min
15:007high25 min
16:005moderate30 min
17:003moderate30 min
18:001low45 min
19:001low45 min

Monthly UV Index Trends in Nantucket

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.

Monthly Maximum UV Index for Nantucket, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Nantucket. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec35689101098642
Data source: Statistical UV Index data for Nantucket, based on information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

Compare Nantucket UV Index with Other United States Cities

The table above highlights how UV exposure in Nantucket compares to other major locations across United States. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.
Nantucket's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
 JanFebMarAprMayJunJulAugSepOctNovDec
Nantucket35689101098642
Chicago UVI34689101098642
Brooklyn UVI35681010998642
New York City UVI35681010998642
Los Angeles UVI46891011111010754
Houston UVI589111112121110975