UV Index Today in Louisville, Kentucky

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.

Louisville's UV Climate

Louisville, located in northern Kentucky, experiences a humid subtropical climate with moderate to high UV exposure during the summer months. The city's midwestern location brings variable weather, but clear summer days can result in high UV index values. Sun protection is important for outdoor activities, especially during peak hours.

Average Annual UV Index

6.7

Peak UV Season

May - September

Sunny Days per Year

195

Typical UV Index by Season in Louisville

Season Typical Midday UV Protection Needed
Summer High to Very High (7-9) SPF 30+, hat, sunglasses; shade from 10 AM – 4 PM
Spring & Fall Moderate to High (4-6) SPF 30+ for extended time outdoors
Winter Low to Moderate (2-3) 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 Jefferson County:

UV and Weather in Jefferson County

Learn about Jefferson 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

Louisville's climate features cold winters and hot, humid summers. UV index values are highest from late spring through early fall, with peak values reaching 8-9 on clear days. Cloud cover is common, but when skies are clear, UV radiation can be intense.

UV Index and Health Impact

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

  • Summer: High to Very High (7-9)
  • Spring/Fall: Moderate to High (4-6)
  • Winter: Low to Moderate (2-3)
  • 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

Louisville's weather is variable, with frequent changes in cloud cover and temperature. Summer brings the highest UV exposure, especially during midday hours. Residents and visitors should use sun protection during outdoor activities, particularly in parks and at outdoor events. Winter UV levels are low but not negligible, especially on sunny, snowy days.

Frequently Asked Questions About UV in Louisville

What is the UV index in Louisville today?

The live UV index for Louisville, KY 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 Louisville?

UV radiation is strongest between 10 AM and 4 PM. Louisville's peak UV season runs May - September, when the midday index typically reaches High to Very High (7-9).

How high does the UV index get in Louisville?

Summer days in Louisville typically reach High to Very High (7-9). Spring and fall usually bring Moderate to High (4-6), while winter values are typically Low to Moderate (2-3).

Do I need sunscreen in Louisville during winter?

Winter UV in Louisville is usually low, so sunburn risk is limited on typical days. Sunscreen is still wise during midday hours or around reflective snow.

How sunny is Louisville compared to other cities?

Louisville averages about 195 sunny days per year with an average annual UV index around 6.7.