UV Index in Williamsport, United States

Last updated: May 3, 2025

Understanding the UV Index in Williamsport, United States, is crucial for safeguarding your skin health, especially during the summer months when UV levels can surge. With a climate categorized as Cfa, residents experience a range of sun exposure throughout the year, but it's during peak hours—often between 10 AM and 2 PM—when the UV Index can reach dangerously high levels of 10. Being aware of these daily UV fluctuations is essential for preventing sunburn and reducing the long-term risks of skin damage. By staying informed, you can enjoy the outdoors while keeping your skin protected from harmful rays.

Hourly UV Index in Williamsport

As the day unfolds, the UV Index reveals a striking pattern in its intensity. Starting gently at 1 at 07:00, the sun's rays begin to gather strength, climbing to 2 by 08:00. A noticeable surge occurs between 09:00 and 10:00, where the index escalates to 5. But the real peak hits at 12:00, where it reaches a soaring 10, remaining steadfast for the following hour. Fortunately, as the afternoon wanes, the intensity gracefully descends, tapering to 8 at 15:00, and gradually dimming to 6 by 16:00, before tapering off to 3 at 17:00, and finally settling back to 1 by 19:00. This dramatic ebb and flow underscores the importance of sun safety, especially 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	2	low	45 min
09:00	3	moderate	30 min
10:00	5	moderate	30 min
11:00	8	very high	15 min
12:00	10	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	3	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Williamsport

Throughout the year, the UV Index shows distinct seasonal changes, with high-risk months typically spanning from March to September. The UV Index peaks in May, June, and July at 10, indicating a very high exposure category with a burn time of just 15 minutes. As spring transitions to summer, residents and visitors should be particularly vigilant during these months, wearing sunscreen, protective clothing, and sunglasses when outdoors. In contrast, the winter months of January, February, November, and December have a more manageable UV Index, categorized as moderate, with burn times of 30 minutes. It is essential for everyone to stay informed and adjust their sun protection strategies accordingly as UV levels fluctuate throughout the year.

Monthly Maximum UV Index for Williamsport, United States

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

The table above highlights how UV exposure in Williamsport 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.

Williamsport'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
Williamsport	3	5	7	9	10	10	10	9	8	7	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