UV Index in Knoxville, United States

Last updated: August 1, 2025

In Knoxville, United States, monitoring the UV Index is crucial for protecting your skin from harmful rays. Awareness of UV levels helps prevent sunburn and supports long-term skin health, making it essential for both residents and visitors. With Knoxville's Dfb climate, characterized by warm summers and varied exposure to sunlight, understanding the local UV index can significantly reduce your risks during peak hours. During the summer months, UV levels can soar as high as 10 between noon and 1 PM, highlighting the importance of sun protection strategies to keep your skin safe while enjoying the outdoors.

Hourly UV Index in Knoxville

As the sun rises, the UV Index gradually climbs, beginning at a mild 1 at 7:00 AM. By 9:00 AM, it reaches 3, prompting early risers to consider sun protection. The intensity peaks at 1:00 PM with a maximum of 10, signaling the most hazardous conditions for unprotected skin. As the afternoon unfolds, the index dips from 9 at 2:00 PM to 6 by 4:00 PM, offering a brief respite. As the day winds down, the UV rays decrease, falling to 2 by 6:00 PM and returning to a safe 1 by 7:00 PM. Stay mindful of these fluctuations to enjoy the sun while safeguarding 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.
TimeUVICategoryTime to Burn
07:001low45 min
08:001low45 min
09:003moderate30 min
10:005moderate30 min
11:007high25 min
12:009very high15 min
13:009very high15 min
14:009very high15 min
15:007high25 min
16:005moderate30 min
17:003moderate30 min
18:002low45 min
19:001low45 min

Monthly UV Index Trends in Knoxville

Throughout the year, UV exposure varies significantly, peaking during late spring and summer months. High-risk months for UV exposure are April through September, where the UV Index frequently reaches levels classified as very high; particularly notable are May, June, and July, when it consistently hits a maximum of 10. Visitors and residents are advised to take precautions during these months, with burn times dramatically reduced to as little as 15 minutes. In contrast, January, February, and November present moderate UV levels, and December has a low index, making sun safety measures less critical during these months. To protect against skin damage, it is essential to wear sunscreen, seek shade, and wear protective clothing, especially between peak months of April and September.

Monthly Maximum UV Index for Knoxville, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Knoxville. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098642
Data source: Statistical UV Index data for Knoxville, 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 Knoxville UV Index with Other United States Cities

The table above highlights how UV exposure in Knoxville 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.
Knoxville'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
Knoxville356910101098642
Los Angeles UVI46891011111010754
Houston UVI589111112121110975