UV Index Today in Denver, Colorado

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.

Denver's UV Climate

Denver, located in the Rocky Mountains of Colorado, experiences a semi-arid climate with extremely high UV exposure due to its high elevation. The city's mile-high altitude, clear skies, and southern latitude result in some of the highest UV radiation levels in the United States. The combination of outdoor activities, mountain recreation, and thin atmosphere makes comprehensive sun protection critical for residents and visitors, especially during high-altitude activities.

Average Annual UV Index

8.9

Peak UV Season

April - September

Sunny Days per Year

300

Typical UV Index by Season in Denver

Season Typical Midday UV Protection Needed
Summer Very High to Extreme (9-11) SPF 30+, hat, sunglasses; shade from 10 AM – 4 PM
Spring & Fall High (6-8) 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 Denver County:

UV and Weather in Denver County

Learn about Denver 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

Denver's high-altitude climate creates extreme UV exposure conditions with very high to extreme UV levels for most of the year. The city receives intense UV radiation due to its elevation of 5,280 feet, which reduces atmospheric filtering of UV rays. UV index values frequently reach 10+ during peak hours, even in winter. Local weather radar shows abundant sunshine throughout the year, with minimal cloud cover providing maximum UV exposure. The thin mountain air means UV radiation is more intense than at sea level.

UV Index and Health Impact

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

  • Summer: Very High to Extreme (9-11)
  • Spring/Fall: High (6-8)
  • 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

Denver's weather patterns create unique UV exposure challenges throughout the year. The city experiences a semi-arid climate with abundant sunshine and minimal precipitation. Summer months bring hot temperatures and maximum UV exposure, while winter months bring snow and cold temperatures but still feature high UV levels due to high elevation and clear skies. The city's mountain location means UV radiation is amplified by snow reflection during winter months. Spring and fall bring variable weather but consistently high UV levels due to elevation and southern latitude.

Frequently Asked Questions About UV in Denver

What is the UV index in Denver today?

The live UV index for Denver, CO 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 Denver?

UV radiation is strongest between 10 AM and 4 PM. Denver's peak UV season runs April - September, when the midday index typically reaches Very High to Extreme (9-11).

How high does the UV index get in Denver?

Summer days in Denver typically reach Very High to Extreme (9-11). Spring and fall usually bring High (6-8), while winter values are typically Low to Moderate (2-4).

Do I need sunscreen in Denver during winter?

It is a good idea. Winter UV in Denver still reaches moderate levels on clear days, so sunscreen is recommended for extended time outdoors.

How sunny is Denver compared to other cities?

Denver averages about 300 sunny days per year with an average annual UV index around 8.9.