UV Index in Williamsport, United States

Last updated: August 1, 2025

Understanding the UV Index is crucial for residents of Williamsport, Pennsylvania, especially given its varied climate in the Dfb zone. As the UV levels can reach a maximum of 10 around midday, being informed helps in preventing sunburn and promoting skin health. With the potential risks of prolonged sun exposure—particularly during the summer months when the UV Index peaks—knowledge of these levels empowers you to take necessary precautions. Protect your skin and enjoy the beautiful outdoors of Williamsport by staying aware of the UV Index and its implications for your health.

Hourly UV Index in Williamsport

As the sun rises, the UV Index gradually climbs, beginning at a mild 1 at 7:00 AM. By 9:00 AM, it reaches 3, prompting early risers to consider sun protection. The intensity peaks at 1:00 PM with a maximum of 10, signaling the most hazardous conditions for unprotected skin. As the afternoon unfolds, the index dips from 9 at 2:00 PM to 6 by 4:00 PM, offering a brief respite. As the day winds down, the UV rays decrease, falling to 2 by 6:00 PM and returning to a safe 1 by 7:00 PM. Stay mindful of these fluctuations to enjoy the sun while safeguarding your skin!

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	8	very high	15 min
13:00	9	very high	15 min
14:00	9	very high	15 min
15:00	7	high	25 min
16:00	5	moderate	30 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, UV exposure varies significantly, peaking during late spring and summer months. High-risk months for UV exposure are April through September, where the UV Index frequently reaches levels classified as very high; particularly notable are May, June, and July, when it consistently hits a maximum of 10. Visitors and residents are advised to take precautions during these months, with burn times dramatically reduced to as little as 15 minutes. In contrast, January, February, and November present moderate UV levels, and December has a low index, making sun safety measures less critical during these months. To protect against skin damage, it is essential to wear sunscreen, seek shade, and wear protective clothing, especially between peak months of April and September.

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	6	9	10	10	10	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