UV Index in Challis, United States

Last updated: May 3, 2025

In Challis, United States, being aware of the UV Index is crucial for safeguarding your skin and overall health. Understanding UV levels helps you take proactive measures to prevent sunburn and reduce long-term skin damage. This picturesque town, nestled in a Dfb climate zone, experiences significant sunlight, particularly during peak hours when UV levels can soar to 11. With such intensity, it's essential to stay informed and protect yourself against harmful rays, ensuring you can enjoy the great outdoors while prioritizing your skin's well-being.

Hourly UV Index in Challis

As the sun rises, the UV Index begins its ascent, starting at a gentle 1 at 07:00. By 09:00, it's at a moderate 3, but the real climb begins as the clock strikes 10:00, where it jumps to 6. The peak arrives at 12:00, hitting a blistering 10, and remains intense with 11 at 13:00 and 14:00. As the afternoon progresses, we see a gradual decline—10 at 15:00, then down to 8 at 16:00 and finally easing to 3 by 18:00. As day turns to dusk, the UV exposure quickly fades to a safe 1 by 19:00. Stay sun-smart during those peak hours, especially between 11:00 and 14:00, when UV 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	2	low	45 min
09:00	3	moderate	30 min
10:00	6	high	25 min
11:00	8	very high	15 min
12:00	10	very high	15 min
13:00	11	extreme	10 min
14:00	11	extreme	10 min
15:00	10	very high	15 min
16:00	8	very high	15 min
17:00	5	moderate	30 min
18:00	3	moderate	30 min
19:00	1	low	45 min

Monthly UV Index Trends in Challis

Throughout the year, UV exposure varies significantly, with the highest risk months typically from March to August. During this period, the UV Index peaks at 11, indicating an extreme exposure category in May, June, and July, where a burn can occur in as little as 10 minutes. Visitors and residents should take extra precautions during these months, such as seeking shade, wearing protective clothing, and applying sunscreen regularly. As summer transitions into fall, UV levels gradually decrease, but September still presents a very high risk with an index of 9. Conversely, winter months, especially December and January, exhibit much lower UV indices, ranging from 2 to 3, which means prolonged exposure is less of a concern. Overall, being UV-aware and practicing sun safety is crucial during the high-risk months.

Monthly Maximum UV Index for Challis, United States

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

The table above highlights how UV exposure in Challis 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.

Challis'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
Challis	3	5	8	9	11	11	11	10	9	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