UV Index in Harvard, United States

Last updated: May 3, 2025

Understanding the UV Index in Harvard, United States, is essential for safeguarding your skin health and preventing sunburn. With a climate zone classified as Dfa, residents need to be particularly aware of daily UV levels, which can peak at a concerning 9 during the midday hours. By recognizing the significance of these levels, you can take proactive steps to protect yourself and your loved ones from harmful ultraviolet radiation. Whether you're enjoying outdoor activities or simply soaking up the sun, knowing the UV Index helps you make informed decisions about sun safety—ensuring you enjoy the beautiful Harvard weather without compromising your health.

Hourly UV Index in Harvard

The UV Index reveals a dynamic pattern throughout the day, starting at a mild 1 at 07:00 and steadily rising as the sun reaches its peak. By 10:00, it escalates to a moderate 6, reaching 8 at 11:00 and peaking at an intense 9 from 12:00 to 13:00. This period signifies the greatest caution for sun exposure, making it essential to seek shade and wear protective clothing. As the afternoon unfolds, the index begins to dip, dropping to 8 at 14:00, then declining further to 7 by 15:00, and tapering down to 1 by 19:00. Overall, it’s a day that encourages sun safety awareness, particularly during the midday hours when UV radiation is at its strongest.

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	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	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

Monthly UV Index Trends in Harvard

Throughout the year, the UV Index experiences significant fluctuations, with the highest risk of harmful exposure occurring from March to September. During this peak season, particularly in April through August, the UV Index reaches levels of 8 to 10, categorizing exposure as very high and reducing the burn time to just 15 minutes. Conversely, the winter months see much lower UV levels; for instance, January and February maintain a moderate index of 3 and 4, while December drops to a low level of 2. Visitors and residents are advised to take extra precautions during high-risk months, especially by wearing sunscreen, protective clothing, and seeking shade when outdoors to minimize the risk of skin damage.

Monthly Maximum UV Index for Harvard, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Harvard. 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 Harvard, 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 Harvard UV Index with Other United States Cities

The table above highlights how UV exposure in Harvard 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.

Harvard'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
Harvard	3	4	6	8	9	10	10	9	8	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