Fremont, Colorado Air Quality Today
AirHistory tracks long-run EPA monitoring rather than live readings, so for the live number check AirNow.gov below. As a baseline, Fremont, Colorado's most recent EPA year (2023) posted a median AQI of 12 (Good) against a 5-year median of 13 and an overall Grade of A. The dominant pollutant is Coarse Particulate Matter (PM10), which tells you which days are most likely to spike.
Check Today's Live AQI in Fremont, Colorado
AirHistory is built on 10 years of EPA Air Quality System records, so it shows you what air quality in Fremont, Colorado typically looks like — not the live reading for this exact hour. For today's real-time AQI, check AirNow.gov (the EPA's official live index) or the AirNow Fire and Smoke Map during wildfire season.
That said, the history is the best predictor of a normal day. In 2023, Fremont, Colorado posted a median AQI of 12 (Good), with 162 "Good" days and 0 days that crossed into "Unhealthy for Sensitive Groups" or worse. The dominant pollutant, Coarse Particulate Matter (PM10), is the one most likely to push today's number up — Coarse particulate matter — particles up to 10 micrometers across — typically comes from dust, construction sites, agriculture, unpaved roads, and natural sources like windblown soil. PM10 is less hazardous than PM2.5 because the larger particles do not penetrate as deeply into the lungs, but high levels still aggravate asthma and irritate airways.
Fremont, Colorado Air Quality Snapshot
| Air Quality Grade | A81/100 |
| 5-Year Median AQI | 13 (Good) |
| Most Recent Median AQI (2023) | 12 (Good) |
| Dominant Pollutant | Coarse Particulate Matter (PM10) |
| 10-Year Trend | Stable (-0.10 AQI/yr) |
| Unhealthy Days (last 5 yr) | 0 |
| National Rank (cleanest = #1) | #20 of 1,020 (2th cleanest percentile) |
| Colorado Rank | #2 of 32 |
What Does the A Grade Mean?
Fremont, Colorado earns an A — it is among the cleanest U.S. cities tracked by EPA monitoring, with median AQI averaging just 13 over the past five years. Days in the "Good" category dominate the calendar; air-quality alerts are rare.
Fremont, Colorado's 5-year median AQI of 13 is 28 points below the national average of 41 — meaningfully cleaner than the typical U.S. metro tracked here. Within Colorado, Fremont, Colorado runs cleaner than the state average of 39 — a positive signal that local conditions (terrain, wind patterns, emission sources) are working in residents' favor.
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 Fremont, Colorado's Air?
The dominant pollutant in Fremont, Colorado is Coarse Particulate Matter (PM10). Coarse particulate matter — particles up to 10 micrometers across — typically comes from dust, construction sites, agriculture, unpaved roads, and natural sources like windblown soil. PM10 is less hazardous than PM2.5 because the larger particles do not penetrate as deeply into the lungs, but high levels still aggravate asthma and irritate airways.
Days by Dominant Pollutant (2023)
| Pollutant | Days as Dominant | Share of Year |
|---|---|---|
| Coarse Particulate Matter (PM10) | 163 | 100% |
Is the Air Getting Better or Worse?
Air quality in Fremont, Colorado has held roughly steady over the past decade, with year-to-year shifts in median AQI of less than half a point. That stability makes the city's long-run grade a reliable signal of what residents can expect day-to-day.
In 2014, Fremont, Colorado posted a median AQI of 15. By 2023 that figure was 12 — a drop of 3 AQI points cleaner across 10 years of EPA records.
Year-by-Year AQI in Fremont, Colorado
| Year | Median AQI | Good Days | Unhealthy Days | Dominant Pollutant |
|---|---|---|---|---|
| 2014 | 15 | 58 | 0 | PM10 |
| 2015 | 11 | 57 | 0 | PM10 |
| 2016 | 14 | 52 | 0 | PM10 |
| 2017 | 11 | 39 | 0 | PM10 |
| 2018 | 15 | 20 | 0 | PM10 |
| 2019 | 13 | 32 | 0 | PM10 |
| 2020 | 11 | 17 | 0 | PM10 |
| 2021 | 15 | 85 | 0 | PM10 |
| 2022 | 12 | 115 | 0 | PM10 |
| 2023 | 12 | 162 | 0 | PM10 |
Health Context for Fremont, Colorado
Across the past five years, this area has logged just 0 days where AQI rose into the "Unhealthy for Sensitive Groups" range or worse — about 0 days per year, or roughly one every other month. That is a low count by national standards.
For most healthy adults, current air quality in this area does not require any change in behavior. People with severe asthma, COPD, or recent cardiac events should still keep an eye on daily AQI alerts, especially during wildfire season. PM10 is largely a near-source pollutant — staying upwind of busy roads, construction, and unpaved areas can substantially reduce exposure.
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.
More about Fremont, Colorado
Fremont, Colorado has an Air Quality Grade of A (excellent) with a 5-year median AQI of 13. The dominant pollutant is Coarse Particulate Matter (PM10), and air quality has been stable 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.