UV Index in Charleston, United States

Last updated: June 2, 2025

Understanding the UV Index is crucial for maintaining skin health in Charleston, where sunny days are a staple of the Cfa climate. The UV Index measures the strength of ultraviolet radiation, which can lead to sunburn and long-term skin damage if proper precautions aren’t taken. With peak UV levels reaching as high as 10 during midday hours, it’s essential for residents and visitors to be aware of these fluctuations and the potential risks they pose. By keeping an eye on the UV Index, you can enjoy the beautiful Charleston sunshine while effectively protecting your skin from harmful effects.

Hourly UV Index in Charleston

The UV Index data for the day reveals a notable rise in solar intensity, peaking at 10 between 1:00 PM and 2:00 PM. Starting from a gentle 1 at 7:00 AM, the index steadily climbs as the sun ascends, reaching a moderate 5 by 10:00 AM, and then surging to 9 at 12:00 PM. As the clock strikes 1:00 PM, the maximum UV Index of 10 alerts outdoor enthusiasts to take precautions. After this peak, a gradual decline begins, dropping to 4 by 5:00 PM, and the day winds down with readings back to 1 by 7:00 PM. Monitoring these fluctuations is essential for enjoying the sunshine safely!

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.
TimeUVICategoryTime to Burn
07:001low45 min
08:002low45 min
09:003moderate30 min
10:005moderate30 min
11:007high25 min
12:009very high15 min
13:0010very high15 min
14:0010very high15 min
15:009very high15 min
16:007high25 min
17:004moderate30 min
18:002low45 min
19:001low45 min

Monthly UV Index Trends in Charleston

Throughout the year, UV exposure varies significantly, with the high-risk months spanning from April to September. During this period, the UV Index reaches very high levels, peaking at 10 in May, June, July, and August, where the burn time is as short as 15 minutes. In contrast, January, February, November, and December present moderate risk with an Index of 3 to 5, allowing up to 30 minutes of safe sun exposure. Residents and visitors should take precautions during the spring and summer months, including wearing protective clothing, using sunscreen with high SPF, and seeking shade during peak hours to minimize the risk of sunburn and long-term skin damage. Remember, even on cloudy days, UV rays can still penetrate, so remain vigilant year-round.

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.
JanFebMarAprMayJunJulAugSepOctNovDec357910101098753
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.
 JanFebMarAprMayJunJulAugSepOctNovDec
Chicago UVI34689101098642
Brooklyn UVI35681010998642
New York City UVI35681010998642
Charleston3579101010108753
Los Angeles UVI46891011111010754
Houston UVI589111112121110975