UV Index in Charleston, United States

Last updated: June 2, 2025

Awareness of the UV Index is crucial for residents and visitors in Charleston, United States, where the combination of warm weather and high sun exposure creates significant risks for skin health. Understanding UV levels is important for preventing sunburn and reducing the long-term effects of sun damage. With Charleston's Cfa climate, characterized by hot summers and moderate humidity, the UV index can soar, peaking at a staggering 11 during midday hours. By staying informed about daily UV levels, you can take the necessary precautions to protect your skin while enjoying all that this beautiful city has to offer.

Hourly UV Index in Charleston

Expect a sunny day with a fluctuating UV Index that peaks at 11 around midday. The morning starts off gentle, with values rising from 1 at 7:00 AM to 4 by 9:00 AM. As the sun climbs higher, the UV Index escalates sharply, reaching 9 by 11:00 AM and hitting its highest point of 11 at both 12:00 PM and 1:00 PM. After the sun’s zenith, the UV levels gradually decline, dropping to 10 at 2:00 PM and tapering off to 1 by 7:00 PM. Remember to protect your skin during those peak hours for a safe and enjoyable day outdoors!

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	9	very high	15 min
12:00	11	extreme	10 min
13:00	11	extreme	10 min
14:00	10	very high	15 min
15:00	8	very high	15 min
16:00	6	high	25 min
17:00	3	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Charleston

Throughout the year, UV Index levels exhibit significant seasonal variations, with high-risk months highlighted between March and August. During this period, the UV Index often reaches very high to extreme levels, particularly in May, June, and July, where it peaks at 11 and suggests a burn time of as little as 10 minutes. Visitors and residents are advised to take precautionary measures, such as wearing sunscreen, protective clothing, and seeking shade during peak hours. In contrast, the lower UV levels in January, December, and November present a moderate risk, with recommended exposure times of 30 and 25 minutes. As the year progresses, it’s crucial to stay informed about these UV changes and adjust sun safety practices accordingly.

Monthly Maximum UV Index for Charleston, United States

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

The table above highlights how UV exposure in Charleston 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.

Charleston'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
Charleston	4	7	8	10	11	11	11	10	9	7	6	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5