UV Index in Williamsport, United States

Last updated: July 2, 2025

Understanding the UV Index is essential for residents of Williamsport, Pennsylvania, where the combination of a humid subtropical climate and varying sun exposure can significantly impact skin health. With peak UV levels reaching as high as 10 during the summer months, being aware of these readings helps prevent sunburn and long-term skin damage. The typical weather in Williamsport often leads to higher UV exposure risks around midday; hence, knowing when to seek shade or apply sunscreen is crucial for maintaining skin health and enjoying the outdoors safely. Stay informed and protect yourself from harmful rays!

Hourly UV Index in Williamsport

The UV Index reveals a dynamic ascent and descent throughout the day, peaking with intensity during midday. Starting at a gentle 1 at 7:00 AM, it climbs steadily, reaching 10 by 1:00 PM and maintaining this highest level until 2:00 PM. This critical window indicates significant sun exposure, and it’s essential to take precautions. As the afternoon progresses, the index begins to taper off, dropping to 8 at 3:00 PM, then gradually falling to 1 by 7:00 PM. This data highlights the importance of being sun-smart during the peak hours to minimize UV exposure risks.

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	9	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 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