Question 1

What is the air quality in Denver today?

Accepted Answer

Current Denver air quality is shown live at the top of this page, updated hourly from the EPA AirNow network. Denver typically averages an annual AQI around 40–55 (Good to Moderate range), but wildfire smoke events in summer can push readings above 150 (Unhealthy). Check the AQI gauge above for today's real-time reading from the Denver metro monitoring stations.

Question 2

What is a good AQI reading for Denver outdoor activities?

Accepted Answer

An AQI of 0–50 is considered Good — perfect for any outdoor activity including running, cycling, and attending outdoor events. AQI 51–100 (Moderate) is acceptable for most healthy adults. If you're planning an outdoor event, Red Rocks show, or run in City Park, aim for days with AQI below 75 for the best experience.

Question 3

Why does Denver have poor air quality?

Accepted Answer

Denver's air quality challenges stem from three main sources: (1) Wildfire smoke — Colorado and neighboring states experience regular summer wildfires that blanket the Front Range with PM2.5 particulate matter. (2) The Denver Brown Cloud — a phenomenon where cold, dense air settles in the South Platte River valley during winter temperature inversions, trapping vehicle emissions and wood-burning smoke. (3) Ozone — Denver's intense sunshine and high concentration of vehicle traffic react to form ground-level ozone, especially on hot summer afternoons.

Question 4

When is Denver air quality worst?

Accepted Answer

Denver experiences two distinct air quality seasons. Winter (December–February) brings temperature inversions that trap particulate matter (PM2.5) near the ground — the famous 'Brown Cloud' is most visible from late November through February. Summer (June–September) brings ozone pollution on hot afternoons and wildfire smoke events that can last days to weeks. The best months for outdoor air quality are typically April, May, and October.

Question 5

Does wildfire smoke affect Denver air quality?

Accepted Answer

Yes — wildfire smoke is now the single largest driver of Denver's worst air quality days. Climate change has extended the wildfire season and increased fire intensity across the West. Denver sits downwind of major fire zones in Colorado, Wyoming, Utah, California, and Oregon. During active fire events, AQI can spike from Good (below 50) to Unhealthy (above 150) within hours. The 2020 wildfire season saw Denver record AQI values above 200 for multiple consecutive days.

Question 6

What is Denver's average AQI?

Accepted Answer

Denver's annual average AQI typically ranges from 40 to 60, placing it in the 'Moderate' category for most of the year. The Denver metro area has made significant air quality improvements over the past 30 years due to vehicle emission standards and industrial regulations. However, Denver still frequently exceeds federal ozone standards on summer days, and wildfire smoke events have increased the number of 'unhealthy' air quality days in recent years.

Question 7

How does Denver's elevation affect air quality?

Accepted Answer

Denver's elevation of 5,280 feet (one mile above sea level) creates a paradox for air quality. On one hand, the thinner atmosphere means fewer air molecules to dilute pollutants — the same amount of smoke or ozone affects residents more at altitude. On the other hand, Denver's elevation means it sits above some pollution layers that affect lower-lying cities. The thin air also means UV radiation is 25% stronger at Denver's elevation, accelerating the chemical reactions that form ground-level ozone on sunny days.

Question 8

What AQI is safe for running in Denver?

Accepted Answer

For healthy adults, running and vigorous exercise is safe at AQI 0–100. At AQI 51–100 (Moderate), sensitive individuals (asthma, heart conditions) should consider reducing intensity or duration. At AQI 101–150 (Unhealthy for Sensitive Groups), healthy adults can still run but should avoid peak ozone hours (noon–6pm) and opt for morning runs. Above AQI 150, most runners should move workouts indoors or to an air-filtered gym. Denver's high altitude amplifies the effect of pollutants on breathing — if in doubt, reduce your effort level.

Question 9

What is the air quality like at Red Rocks Amphitheatre?

Accepted Answer

Red Rocks Amphitheatre sits at 6,450 feet elevation in Morrison, CO — about 1,200 feet higher than downtown Denver and in the foothills. Air quality at Red Rocks is generally similar to Denver's readings but can differ due to its mountain canyon location. Wind patterns in the canyon can concentrate or disperse smoke differently than downtown. On high-AQI days, Red Rocks outdoor shows may be particularly challenging for those with respiratory conditions. Always check the current AQI before attending a Red Rocks show — especially during summer wildfire season.

Question 10

Is Denver's air quality getting better or worse?

Accepted Answer

The picture is mixed. On one hand, Denver has made dramatic improvements since the 1970s–1990s era of the severe 'Brown Cloud' — tighter vehicle emission standards and the shift from coal heating have significantly reduced winter particulate matter. On the other hand, wildfire smoke has increased sharply since 2017 due to climate change, adding more 'unhealthy' days per year than in previous decades. Ground-level ozone also remains a persistent challenge that hasn't improved much despite other gains. Overall, Denver's air is cleaner than it was 30 years ago, but the wildfire trend is moving in the wrong direction.

Question 11

Which Denver neighborhoods have the worst air quality?

Accepted Answer

Air quality varies significantly across Denver's metro area. Neighborhoods near I-25, I-70, and heavy industrial corridors tend to have higher pollution levels: Globeville, Elyria-Swansea, and Swansea near the I-70 and I-25 junction have historically been among the most impacted. The Denver metro area's EPA monitoring network measures air quality across multiple stations. During wildfire events, differences between neighborhoods become smaller as smoke blankets the entire region uniformly. The western suburbs (Lakewood, Golden) near the Foothills often have slightly cleaner air due to mountain breezes.

City	Avg Annual AQI	Primary Challenge	Unhealthy Days/yr
Denver, COYou are here	47	Wildfire smoke + ozone	20
Los Angeles, CA	68	Traffic ozone + wildfires	45
Salt Lake City, UT	54	Winter inversions	28
Phoenix, AZ	52	Dust storms + ozone	24
Seattle, WA	38	Wildfire smoke (seasonal)	12
Chicago, IL	42	Industrial + traffic	16
New York, NY	45	Traffic + urban density	18

Denver Air QualityToday 2026

Current Air Quality Index

Health Impact Guide

Denver Air Quality Map

Today's AQI Trend

7-Day Denver Weather Forecast

Denver Climate — Monthly Averages

Understanding Denver Air Quality

The Mile High Effect

Wildfire Smoke Season

The "Brown Cloud"

Ozone Patterns in Denver

Data Sources & Methodology

Denver Air Quality by Season

Denver Air Quality vs. Other Cities

Denver Air Quality: Frequently Asked Questions

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