Median AQI
32
Good
Colorado · County air quality · 2025
Archuleta County, Colorado
Median AQI 32 (Good). 79.5% of monitored days rated Good, direct from EPA Air Quality System stations.
- 32
- Median AQI
- 79.5%
- Good-air days
- 0
- Unhealthy days
- 51%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Archuleta County's air is good on balance, cleaner than the median US county, a median AQI of 32 with 79.5% of 303 monitored days in the Good band, driven mainly by Ozone.
- 32
- median AQI · Good
- 79.5%
- days rated Good
- Ozone
- main pollutant
- 51%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 115.
Data updated July 2026
- Good · 241 d · 79.5%
- Moderate · 60 d · 19.8%
- USG · 2 d · 0.7%
How did Archuleta County's air break down in 2025?
Across 303 monitored days, 241 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 115 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 303 days monitored. Median AQI: 32 (Good).
Insights: Archuleta County, Colorado. EPA monitors recorded a median Air Quality Index of 32 across 303 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 241 (80%) fell in the Good band (AQI 0–50), 60 (20%) registered Moderate readings, and 2 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 64, while the worst single-day peak hit 115 (USG). Residents averaged about 23.9 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (237 days), PM2.5 (58 days), PM10 (8 days). Across the 2020–2025 trend window, good days shifted by -61 and the median AQI moved -11 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 115, usg but never Unhealthy. Nearby counties show comparable readings: Adams (50.2% good, AQI 50); Alamosa (90.8% good, AQI 24); Arapahoe (47.3% good, AQI 51); Boulder (50.9% good, AQI 50); Clear Creek (64.4% good, AQI 48); Delta (88.0% good, AQI 28).
Air Quality Summary
Good Days
79.5%
241 of 303 monitored days
4.5pp vs 75% target
Max AQI Recorded
115
USG
Health Grade
Good
90th-pct AQI 64
Archuleta County, Good days share 79.5%
National avg
Share of monitored days at AQI 0-50 (Good band).
Archuleta County, Unhealthy-or-worse share 0.0%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
AQI Day Breakdown (2025)
Distribution of 303 monitored days across EPA AQI categories.
Good
241
80%
Moderate
60
20%
USG
2
1%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Archuleta County.
- Ozone · 237 days · 78.2%
- PM2.5 · 58 days · 19.1%
- PM10 · 8 days · 2.6%
Health Impact Assessment
Good
Archuleta County's air quality is rated Good based on 79.5% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 79.5% of monitored days in 2025, with a median AQI of 32. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 237 of 303 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Archuleta County. Best year: 2024 (349 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 302 | 63 | 0 | 0 | 43 | 93 |
| 2021 | 269 | 96 | 0 | 0 | 45 | 93 |
| 2022 | 313 | 48 | 3 | 0 | 42 | 227 |
| 2023 | 349 | 15 | 1 | 0 | 35 | 120 |
| 2024 | 349 | 17 | 0 | 0 | 32 | 80 |
| 2025 | 241 | 60 | 2 | 0 | 32 | 115 |
How does Archuleta County compare?
How Archuleta County compares
Good-day share better than US avg
Archuleta County 79.5%
Adams County, Colorado 50.2%
US average 76.5%
Median AQI better than US avg
Archuleta County 32
Adams County, Colorado 50
US average 38
Unhealthy days / yr about average
Archuleta County 0
Adams County, Colorado 0
US average 0
Other Counties in Colorado
Air quality comparison for nearby counties in Colorado.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Archuleta County.
Clay County, Alabama
AQI 32 · 85.4% good
Elmore County, Alabama
AQI 32 · 97.2% good
Harrison County, West Virginia
AQI 32 · 73.3% good
Klamath County, Oregon
AQI 32 · 71.3% good
Liberty County, Florida
AQI 32 · 97.7% good
Schoolcraft County, Michigan
AQI 32 · 89.4% good
What Archuleta County's air means for you
The air here stays in the breathable range year-round, with Ozone the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-Ozone days, the guide explains what a median of 32 means for exposure. Health guidance
- See how Archuleta County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Archuleta County with its Colorado neighbours before drawing a conclusion about the region. All of Colorado
Based on 303 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
More Air Quality Data
Air Quality Guides
Frequently Asked Questions
What is the air quality in Archuleta County, Colorado? ▼
Archuleta County has a median Air Quality Index (AQI) of 32, rated "Good." 79.5% of monitored days (241 out of 303) had good air quality in 2025.
What is the main pollutant in Archuleta County? ▼
The primary pollutant in Archuleta County is Ozone (O3), which was the main AQI driver on 237 days (78% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Archuleta County have? ▼
In 2025, Archuleta County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 115.
Is the air quality in Archuleta County getting better or worse? ▼
Air quality in Archuleta County is worsening based on 5-year trends (2020-2025). Best year: 2024 with 349 good days. Worst year: 2025 with 241 good days.
What does AQI 32 mean for health? ▼
Archuleta County's median AQI of 32 falls in the "Good" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Archuleta County compare to other counties in Colorado? ▼
Archuleta County has 79.5% good air days. Nearby counties in Colorado: Adams (50.2% good), Alamosa (90.8% good), Arapahoe (47.3% good), Boulder (50.9% good), Clear Creek (64.4% good), Delta (88.0% good).
What is the 90th percentile AQI in Archuleta County? ▼
The 90th percentile AQI for Archuleta County is 64, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 115 (USG).
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer.
Every figure on PlainAir is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.