UV Index in Harvard, United States

Last updated: August 1, 2025

Staying aware of the UV Index is crucial for residents of Harvard, United States, particularly as the region experiences a Dfa climate, characterized by hot summers and cold winters. Understanding the UV levels throughout the day is essential for sunburn prevention and long-term skin health. With peak UV exposure often reaching levels as high as 11 around midday, it becomes vital to take protective measures to shield yourself from harmful rays. By keeping an eye on the UV Index, Harvard residents can enjoy the outdoors while safeguarding their skin against the risks associated with excessive sun exposure.

Hourly UV Index in Harvard

As the sun climbs higher, the UV Index takes a dramatic leap throughout the day. Starting at a gentle 1 at 07:00, it gradually rises to 3 by 09:00. The real intensity kicks in later, peaking at an impressive 11 around 13:00, a critical time when sun protection is essential. From there, a gradual decline begins, with readings of 10 at 14:00, 9 at 15:00, and tapering off to 3 by 18:00. Finally, the day winds down, returning to 1 by 19:00. It’s a vivid reminder of how important it is to safeguard against UV exposure during the sun’s most potent hours!

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	1	low	45 min
09:00	2	low	45 min
10:00	4	moderate	30 min
11:00	6	high	25 min
12:00	8	very high	15 min
13:00	10	very high	15 min
14:00	10	very high	15 min
15:00	8	very high	15 min
16:00	6	high	25 min
17:00	4	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Harvard

The UV Index experiences significant fluctuations throughout the year, with critical changes occurring from March to September. The high-risk months for UV exposure are April through August, where the index peaks at 11 in June and July, indicating an extreme exposure category with a burn time of just 10 minutes. Visitors and residents should take precautions during these months by wearing protective clothing, applying sunscreen regularly, and seeking shade during peak hours. As the index decreases in the fall and winter, particularly in January, February, and November, it remains essential to stay vigilant as UV levels can still pose moderate risks, especially at midday.

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
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
Harvard	3	5	6	9	10	11	11	10	8	6	4	3
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