UV Index in Williamstown, United States

Last updated: July 2, 2025

In Williamstown, United States, understanding the UV Index is crucial for safeguarding your skin health. With UV levels reaching a maximum of 10 around midday, it’s essential to stay informed to prevent sunburn and long-term skin damage. This picturesque town, characterized by a Cfa climate, experiences varying UV exposure that can significantly impact outdoor activities. By monitoring the UV Index, residents and visitors alike can enjoy the beautiful sunny days while taking the necessary precautions to protect against harmful UV rays.

Hourly UV Index in Williamstown

The UV Index chart reveals a dynamic daily pattern of solar intensity. Starting early in the day, the UV Index remains low, peaking at 1 by 08:00. However, as the sun reaches its zenith, the index surges dramatically—hitting 7 by 11:00 and soaring to a maximum of 10 between 13:00 and 14:00. This signals a critical window for sun exposure, where protection is essential. As the afternoon progresses, the UV levels begin to decline, dropping to 4 by 17:00, before tapering off to 1 again by evening. To stay safe, it's vital to be cautious during those peak 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	3	moderate	30 min
10:00	5	moderate	30 min
11:00	7	high	25 min
12:00	9	very high	15 min
13:00	10	very high	15 min
14:00	10	very high	15 min
15:00	9	very high	15 min
16:00	7	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 Williamstown

Throughout the year, UV exposure changes significantly, with high-risk months identified from April to September, when the UV Index reaches notably high levels of 9 to 10. During these months, burn times are critically reduced to just 15 minutes, requiring extra caution. March marks the transition to higher UV levels, with an index of 7 and a 25-minute burn time, while January and February begin with a moderate UV Index of 3 to 5 and longer burn times of 30 minutes. As we move into the fall, UV exposure decreases, dropping to 4 in November and 3 in December. Visitors and residents are advised to protect their skin by wearing sunscreen, protective clothing, and seeking shade, particularly during high-risk months, to minimize the risk of UV-related skin damage.

Monthly Maximum UV Index for Williamstown, United States

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

The table above highlights how UV exposure in Williamstown 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.

Williamstown'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
Williamstown	3	5	7	9	10	10	10	9	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