UV Index in Alton, United States

Last updated: July 2, 2025

In Alton, United States, staying informed about the UV Index is crucial for safeguarding your skin and overall health. Understanding UV levels helps prevent sunburn and reduces the long-term risks associated with skin damage. With a Dfb climate, Alton experiences a range of UV exposure throughout the year, peaking at levels 9 during midday hours, which can lead to significant skin risks if proper precautions aren't taken. By being aware of the UV Index, residents can enjoy the outdoors while effectively protecting themselves against harmful rays.

Hourly UV Index in Alton

The UV Index for today reveals a dynamic shift in solar intensity throughout the day. Starting with a gentle maximum of 1 at 7:00 AM, the sunlight gradually intensifies, peaking at 9 from 12:00 PM to 1:00 PM. This period, marked by high UV levels, urges caution for outdoor activities. As the afternoon unfolds, the index begins a steady decline, tapering off to 3 by 5:00 PM and returning to a mild 1 by 7:00 PM. It's a day perfectly suited for sun safety practices, with the highest exposure time being between 11:00 AM and 1:00 PM. Enjoy the sun, but remember to protect 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	2	low	45 min
09:00	4	moderate	30 min
10:00	6	high	25 min
11:00	8	very high	15 min
12:00	9	very high	15 min
13:00	9	very high	15 min
14:00	8	very high	15 min
15:00	6	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 Alton

Throughout the year, UV exposure varies significantly, with high-risk months typically from April to August, where the UV Index peaks at levels of 8 to 10, resulting in a very high exposure category and a quick burn time of just 15 minutes. In contrast, the winter months of January, February, and December feature a much lower UV Index, ranging from 2 to 4, which is classified as low to moderate, allowing for longer exposure times of 30 to 45 minutes without significant risk. To protect against harmful UV rays, it’s crucial for visitors and residents alike to use sunscreen, wear protective clothing, and seek shade during the peak sun hours, especially from April to August when sun safety practices should be a top priority.

Monthly Maximum UV Index for Alton, United States

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

The table above highlights how UV exposure in Alton 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.

Alton'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
Alton	3	4	5	8	9	10	9	9	7	5	3	2
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
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5