UV Index in Williams, United States

Last updated: July 2, 2025

In Williams, Arizona, understanding the UV Index is essential for maintaining skin health and preventing sunburn. With the region’s Csb climate offering plenty of sunshine, particularly during the summer months, residents and visitors need to be mindful of varying UV levels throughout the day. For instance, the UV Index in Williams peaks at 12 between noon and 1 PM, indicating a high risk of harm from unprotected sun exposure. By staying aware of these UV levels, you can make informed choices about sun protection, ensuring your time outdoors is both enjoyable and safe.

Hourly UV Index in Williams

Experience a sunny day with fluctuating UV Index levels! Starting from a gentle 1 at 07:00, the intensity gradually climbs to reach a peak of 12 at both 12:00 and 13:00. As the sun rises higher, the UV Index hits a striking 11 at 11:00 and 14:00, indicating a need for protective measures. After 15:00, the levels start to decline, dropping to 5 by 16:00 and returning to a mild 1 by 18:00. Plan your outdoor activities wisely and remember, from 10:00 to 14:00, the sun's rays are at their strongest!

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	3	moderate	30 min
09:00	5	moderate	30 min
10:00	8	very high	15 min
11:00	11	extreme	10 min
12:00	12	extreme	10 min
13:00	12	extreme	10 min
14:00	11	extreme	10 min
15:00	8	very high	15 min
16:00	5	moderate	30 min
17:00	3	moderate	30 min
18:00	1	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Williams

The UV Index varies significantly throughout the year, highlighting high-risk months during which sun exposure requires heightened caution. From February to August, the UV Index reaches levels between 8 and 12, indicating very high to extreme exposure categories, with burn times as short as 10 minutes. Notably, April through July presents the greatest risk, making it crucial for visitors and residents to protect their skin through the use of sunscreen, protective clothing, and shade during peak hours. September and October see a gradual decline (UV Index 10 and 8, respectively), but still demand caution. As winter approaches in November and December, the UV Index decreases to 6 and 4, transitioning into a high to moderate exposure category, with burn times increasing back to 25 and 30 minutes. It’s essential for everyone to remain aware of these seasonal changes to ensure their safety while enjoying outdoor activities.

Monthly Maximum UV Index for Williams, United States

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

The table above highlights how UV exposure in Williams 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.

Williams'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
Los Angeles UVI	4	6	8	9	10	11	11	10	10	7	5	4
Williams	4	8	9	11	12	12	12	11	10	8	6	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5