UV Index in Cambridge, United States

Last updated: June 2, 2025

Understanding the UV Index is crucial for residents of Cambridge, Massachusetts, as it serves as a vital tool in safeguarding against harmful ultraviolet radiation. With peak UV levels reaching as high as 10 during midday hours, awareness of these fluctuations can significantly aid in preventing sunburns and promoting long-term skin health. Cambridge's Dfb climate brings a unique blend of seasonal weather patterns, which can influence UV exposure risks. By keeping a close eye on the UV Index, residents can enjoy the sunshine while protecting their skin against potential harm.

Hourly UV Index in Cambridge

The UV Index reaches its peak during the midday hours, showcasing a vibrant sun's intensity. Starting with a gentle 1 at 07:00, it gradually escalates to 3 by 08:00. As the day progresses, the index soars to 5 at 09:00, hitting 7 by 10:00. The real highlight occurs between 11:00 and 13:00, when it peaks at an impressive 10, urging everyone to take caution. Following this, the index begins a slow descent, dropping to 9 at 14:00 and gradually declining to 5 by 16:00. By 18:00, it reduces to 2, finally settling back at 1 by 19:00. This hourly data highlights the importance of sun safety during the peak hours of the day.

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.
Time	UVI	Category	Time to Burn
07:00	1	low	45 min
08:00	3	moderate	30 min
09:00	5	moderate	30 min
10:00	7	high	25 min
11:00	9	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	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Cambridge

Throughout the year, UV Index levels exhibit significant seasonal variation, influencing sun exposure and the risk of skin damage. From January to March, UV exposure is generally low to moderate, with the highest burn time of 45 minutes in January decreasing to 30 minutes by February and March. April to August marks a critical period with very high UV levels, peaking in June at an index of 10, where the burn time shrinks to just 15 minutes. Following this peak, UV intensity slightly decreases in September (UV Index 7), allowing for a longer burn time of 25 minutes, before tapering off again in the last quarter of the year to moderate levels. Thus, residents and visitors are advised to exercise caution and use sun protection—from April through August, especially during midday hours, to minimize the risk of skin damage.

Monthly Maximum UV Index for Cambridge, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Cambridge. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.

Data source: Statistical UV Index data for Cambridge, 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 Cambridge UV Index with Other United States Cities

The table above highlights how UV exposure in Cambridge 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.

Cambridge's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cambridge	2	4	5	8	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