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AirHistory

What Is the Air Quality in Garfield, Colorado?

Garfield, Colorado has an Air Quality Grade of C (fair) with a 5-year median AQI of 50. The dominant pollutant is Ground-Level Ozone, and air quality has been worsening over the past decade.

Garfield, Colorado Air Quality Snapshot

Air Quality GradeC54/100
5-Year Median AQI50 (Good)
Most Recent Median AQI (2023)54 (Moderate)
Dominant PollutantGround-Level Ozone
10-Year TrendWorsening (+0.79 AQI/yr)
Unhealthy Days (last 5 yr)23
National Rank (cleanest = #1)#919 of 1,020 (90th most polluted percentile)
Colorado Rank#26 of 32

What Does the C Grade Mean?

Garfield, Colorado earns a C — air quality is fair, but not great. With a 5-year median AQI of 50, the city sees a meaningful number of "Moderate" days each year, when the EPA flags air as a concern for unusually sensitive people.

Garfield, Colorado's 5-year median AQI of 50 is 9 points above the national average of 41 — meaningfully more polluted than the typical U.S. metro tracked here. Within Colorado, Garfield, Colorado runs more polluted than the state average of 39 — local sources or geography are concentrating pollution above the state's typical reading.

For context within Colorado: Alamosa, Colorado currently holds the state's cleanest grade (A, AQI 14), while Jefferson, Colorado sits at the bottom (D, AQI 47).

What's in Garfield, Colorado's Air?

The dominant pollutant in Garfield, Colorado is Ground-Level Ozone. Ground-level ozone forms when sunlight reacts with vehicle exhaust and industrial emissions. It is worst on hot, sunny, stagnant summer days. Ozone irritates the lungs, triggers asthma attacks, and reduces lung function — even healthy adults can feel chest tightness and shortness of breath after exercising in elevated ozone.

Days by Dominant Pollutant (2023)

PollutantDays as DominantShare of Year
Ground-Level Ozone36099%
Fine Particulate Matter (PM2.5)51%

Is the Air Getting Better or Worse?

Air quality in Garfield, Colorado has been getting worse over the past decade, with median AQI climbing by roughly 0.8 points per year. That bucks the national trend of broad improvement, and most often reflects either growing wildfire smoke exposure (particularly across the West) or rising local emissions from population and freight growth.

In 2014, Garfield, Colorado posted a median AQI of 44. By 2023 that figure was 54 — a rise of 10 AQI points dirtier across 10 years of EPA records.

Year-by-Year AQI in Garfield, Colorado

YearMedian AQIGood DaysUnhealthy DaysDominant Pollutant
2014442992Ozone
20154526010Ozone
2016472631Ozone
2017472401Ozone
20184821416Ozone
2019482482Ozone
2020482325Ozone
20214919811Ozone
2022492212Ozone
2023541663Ozone

Health Context for Garfield, Colorado

Across the past five years, this area has logged just 23 days where AQI rose into the "Unhealthy for Sensitive Groups" range or worse — about 5 days per year, or roughly one every other month. That is a low count by national standards.

Healthy adults can continue normal outdoor activity in most weather, but should pay attention to AQI alerts during the worst pollution windows. People with asthma, heart disease, or pregnancy should reduce prolonged or intense outdoor exertion on flagged days, and consider running an indoor HEPA air cleaner during peak season. Because ozone peaks in the afternoon on hot sunny days, plan outdoor exercise for early morning or after sunset on bad-air days.

How This Grade Is Calculated

The AirHistory Air Quality Grade combines four signals: the 5-year median AQI (40% of the score), the 10-year trend direction (30%), the count of unhealthy days per year (20%), and the dominant pollutant type (10%). All four come directly from the EPA Air Quality System (AQS), which aggregates readings from federally certified monitors. Read the full methodology.

Garfield, Colorado has an Air Quality Grade of C (fair) with a 5-year median AQI of 50. The dominant pollutant is Ground-Level Ozone, and air quality has been worsening over the past decade.

The data source behind this answer is the EPA Air Quality System (AQS). Every figure on the page traces back to that source; the methodology page describes the inputs and the refresh cadence in full detail.

For readers turning this answer into action: cross-reference against the underlying the EPA Air Quality System (AQS) record before acting on time-sensitive decisions. The site renders the data as it was published; subsequent revisions can shift the picture, and the live federal data is always the authoritative current reference.

Source: EPA Outdoor Air Quality Data, 2026.