UV Index Today in Knoxville, Tennessee

Current UV
Today's Max

Hourly UV Forecast

low moderate high very high extreme

Surface Type

Reflective surfaces increase your UV exposure — snow reflects up to 90%, sand about 20%.

Safe Exposure Time

Estimated burn times based on the Fitzpatrick scale for skin color and today's maximum UV index of . Tap your skin type:

Very fair skin, always burns, never tans

Time until burn
With SPF 15*
With SPF 30*

*Assumes proper application of broad-spectrum sunscreen with reapplication every 2 hours. Estimates follow WHO guidance and satellite-derived data — see how our data works.

Sun Times

Dawn
Sunrise
Solar Noon
Sunset
Dusk
Day Length
Morning Golden Hour Ends
Evening Golden Hour

Important Safety Information

General Guidelines

These exposure times are estimates based on scientific research and should be used as general guidelines only. Individual responses to UV exposure may vary.

Affecting Factors

UV exposure is affected by: time of day, season, altitude, cloud cover, reflection from surfaces, and individual skin sensitivity.

Protection Tips

Seek shade during peak UV hours (10 AM - 4 PM), wear protective clothing, use broad-spectrum sunscreen, and monitor the UV index regularly.

Medical Advice

Consult a healthcare provider for personalized sun protection advice, especially if you have a history of skin conditions or take medications that increase sun sensitivity.

Knoxville's UV Climate

Knoxville sits in the Tennessee Valley between the Cumberland Plateau and the Great Smoky Mountains, and its UV picture spans both: humid valley summers with strong midday sun, and quick access to high-elevation trails where UV climbs with every thousand feet. Boaters on the Tennessee River and Norris Lake, Vol fans filling Neyland Stadium through sunny September afternoons, and hikers heading up to Smokies ridgelines all face more exposure than the valley's hazy skies suggest.

Average Annual UV Index

6.8

Peak UV Season

April - September

Sunny Days per Year

204

Typical UV Index by Season in Knoxville

Season Typical Midday UV Protection Needed
Summer Very High (8-10) SPF 30+, hat, sunglasses; shade from 10 AM – 4 PM
Spring & Fall Moderate to High (5-8) SPF 30+ for extended time outdoors
Winter Low to Moderate (2-4) Sunscreen for long midday exposure; more on snow

UV Index in Nearby Cities

Practical Tips for Outdoor Activities

Make the most of outdoor activities while staying safe in Knox County:

UV and Weather in Knox County

Learn about Knox County's unique climate patterns, UV radiation levels, and how they affect your daily life. Enter your zip code for location-specific weather radar data and UV forecasts to help you make informed decisions about outdoor activities and sun protection.

Climate and UV Patterns

Knoxville's humid subtropical climate brings hot, humid summers with midday UV index values of 8-10 on clear days. The famous Smoky Mountain haze softens the view but not the burn — humidity-derived haze scatters visible light while letting most UV through. Elevations in the nearby Smokies add roughly 4-5% UV per thousand feet, making a Clingmans Dome day noticeably stronger than a downtown one.

UV Index and Health Impact

Understanding UV radiation levels is crucial for protecting your health. Typical clear-day UV index values in Knoxville through the year:

  • Summer: Very High (8-10)
  • Spring/Fall: Moderate to High (5-8)
  • Winter: Low to Moderate (2-4)
  • Peak UV hours: 10 AM - 4 PM
  • Cloud cover can reduce UV by 20-40%, but does not eliminate it
  • Clear skies bring maximum UV exposure

Local Weather Patterns

Valley summers run hazy, hot, and humid with scattered afternoon thunderstorms; mornings through early afternoons stay mostly sun-exposed. Fall brings the year's clearest skies right as football season packs 100,000 people into open stadium seating for hours. Winters are mild and changeable, with sunny spells reaching moderate midday UV — relevant for the year-round trail and greenway crowd.

Frequently Asked Questions About UV in Knoxville

What is the UV index in Knoxville today?

The live UV index for Knoxville, TN is shown at the top of this page and updates throughout the day, along with today's maximum and an hourly forecast.

When is the sun strongest in Knoxville?

UV radiation is strongest between 10 AM and 4 PM. Knoxville's peak UV season runs April - September, when the midday index typically reaches Very High (8-10).

How high does the UV index get in Knoxville?

Summer days in Knoxville typically reach Very High (8-10). Spring and fall usually bring Moderate to High (5-8), while winter values are typically Low to Moderate (2-4).

Do I need sunscreen in Knoxville during winter?

Winter UV in Knoxville is modest but non-zero; clear-day hikes, especially at elevation in the Smokies, justify sunscreen even in the cool months.

How sunny is Knoxville compared to other cities?

Knoxville averages about 204 sunny days per year with an average annual UV index around 6.8.