Median AQI
46
Good
Colorado · County air quality · 2024
Rio Blanco County, Colorado
Median AQI 46 (Good). 72.7% of monitored days rated Good, direct from EPA Air Quality System stations.
- 46
- Median AQI
- 72.7%
- Good-air days
- 0
- Unhealthy days
- 27%
- Cleaner than US counties
Rio Blanco County's 2024 annual median AQI is 46 (Good), with 72.7% Good days
According to the U.S. EPA Air Quality System, Rio Blanco County, Colorado posted a 2024 median AQI of 46 (Good) across 366 monitored days, with 72.7% rated Good and 0 unhealthy or worse. This is an annual comparison, not today's advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US
- Rio Blanco County's 72.7% Good-day share places it cleaner than 27% of US counties in 2024.
- Closest median-AQI peer
- Santa Clara County (55.4% Good, median AQI 47) is the closest nationwide median-AQI peer to Rio Blanco County.
- 2020–2024 trend
- Rio Blanco County's floor-qualifying Good-day share is stable from 2020 to 2024 (72.1% → 72.7%).
- Median AQI
- Median AQI: 46
The verdict
According to EPA Air Quality System monitoring data, Rio Blanco County's air is good on balance, more polluted than the median US county, a median AQI of 46 with 72.7% of 366 monitored days in the Good band, driven mainly by Ozone.
- 46
- median AQI · Good
- 72.7%
- days rated Good
- Ozone
- main pollutant
- 27%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 142.
Annual release change
What changed in the 2024 EPA annual release
- Rio Blanco County's Good-day share rose from 67.7% to 72.7% between the 2023 and 2024 EPA annual releases, a change of +5.0 percentage points.
- Rio Blanco County's peak single-day AQI fell from 166 to 142 between the 2023 and 2024 EPA annual releases, a change of -24 points.
- Rio Blanco County's Unhealthy-category days fell from 1 to 0 between the 2023 and 2024 EPA annual releases, a change of -1 days.
Data updated August 2026
- Good · 266 d · 72.7%
- Moderate · 96 d · 26.2%
- USG · 4 d · 1.1%
How did Rio Blanco County's air break down in 2024?
Across 366 monitored days, 266 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 142 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2024). 366 days monitored. Median AQI: 46 (Good).
Insights: Rio Blanco County, Colorado. EPA monitors recorded a median Air Quality Index of 46 across 366 measured days in 2024, earning a Good classification and a Moderate health grade. Of those days, 266 (73%) fell in the Good band (AQI 0–50), 96 (26%) registered Moderate readings, and 4 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 67, while the worst single-day peak hit 142 (USG). Residents averaged about 21.8 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (351 days), PM2.5 (14 days), NO2 (1 days). Across the 2020–2024 trend window, the share of monitored days rated Good shifted by +0.6 points and the median AQI moved +1 points, placing the multi-year trajectory at stable. The worst single reading over the 2020–2024 window was AQI 142, usg but never Unhealthy. Nearby counties show comparable readings: Adams (55.1% good, AQI 49); Alamosa (91.5% good, AQI 25); Arapahoe (58.1% good, AQI 48); Archuleta (83.0% good, AQI 34); Boulder (58.4% good, AQI 48); Chaffee (66.0% good, AQI 48).
Air Quality Summary
Good Days
72.7%
266 of 366 monitored days
-2.3pp vs 75% target
Max AQI Recorded
142
USG
Health Grade
Moderate
90th-pct AQI 67
Rio Blanco County, Good days share 72.7%
National avg
Share of monitored days at AQI 0-50 (Good band).
Rio Blanco 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 (2024)
Distribution of 366 monitored days across EPA AQI categories.
Good
266
73%
Moderate
96
26%
USG
4
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 Rio Blanco County.
- Ozone · 351 days · 95.9%
- PM2.5 · 14 days · 3.8%
- NO₂ · 1 days · 0.3%
Health Impact Assessment
Moderate
Rio Blanco County's air quality is rated Moderate based on 72.7% good air days. No unhealthy air days were recorded in 2024.
Air quality was acceptable on 72.7% of monitored days in 2024, with a median AQI of 46. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 351 of 366 monitored days.
5-Year Air Quality Trend
Air quality is stable in Rio Blanco County. Highest Good-day share: 2024 (72.7%, 266 of 366 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 263 | 99 | 3 | 0 | 45 | 115 |
| 2021 | 212 | 148 | 4 | 1 | 48 | 156 |
| 2022 | 243 | 120 | 2 | 0 | 47 | 122 |
| 2023 | 247 | 113 | 4 | 1 | 47 | 166 |
| 2024 | 266 | 96 | 4 | 0 | 46 | 142 |
How does Rio Blanco County compare?
How Rio Blanco County compares
Good-day share worse than US avg
Rio Blanco County 72.7%
Santa Clara County, California 55.4%
US average 76.0%
Median AQI worse than US avg
Rio Blanco County 46
Santa Clara County, California 47
US average 39
Unhealthy days / yr better than US avg
Rio Blanco County 0
Santa Clara County, California 0
US average 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Rio Blanco County (46), not geographic neighbors.
Santa Clara County, California
Median AQI 47 · 55.4% Good-day share
Contra Costa County, California
Median AQI 48 · 53.5% Good-day share
Johnston County, Oklahoma
Median AQI 44 · 74.7% Good-day share
Yancey County, North Carolina
Median AQI 44 · 81.9% Good-day share
Alameda County, California
Median AQI 49 · 53.0% Good-day share
Pontotoc County, Oklahoma
Median AQI 43 · 71.6% Good-day share
Same primary pollutant: Ozone
Ozone led the AQI on the most monitored days here. These peers share that driver and the closest Good-day share (a second relationship type beyond median-AQI neighbors).
Jefferson County, Oklahoma
81.0% Good-day share · median AQI 42
Weston County, Wyoming
87.7% Good-day share · median AQI 39
Big Horn County, Wyoming
89.2% Good-day share · median AQI 39
Sumter County, Georgia
93.4% Good-day share · median AQI 38
Columbia County, Georgia
94.2% Good-day share · median AQI 36
Chattooga County, Georgia
96.3% Good-day share · median AQI 39
Colorado counties on the map
Geographic containment only, other monitored counties in Colorado, independent of AQI or pollutant match.
What Rio Blanco 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 46 means for exposure. Health guidance
- See how Rio Blanco County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Rio Blanco County with its Colorado neighbours before drawing a conclusion about the region. All of Colorado
Based on 366 EPA-monitored days in 2024; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
Keep exploring the annual AQI record
Air-quality reading list
Frequently Asked Questions
What is the air quality in Rio Blanco County, Colorado? ▼
Rio Blanco County has a median Air Quality Index (AQI) of 46, rated "Good." 72.7% of monitored days (266 out of 366) had good air quality in 2024.
What is the main pollutant in Rio Blanco County? ▼
The primary pollutant in Rio Blanco County is Ozone (O3), which was the main AQI driver on 351 days (96% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Rio Blanco County have? ▼
In 2024, Rio Blanco County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 142.
Is the air quality in Rio Blanco County getting better or worse? ▼
Air quality in Rio Blanco County is stable across floor-qualifying years (2020-2024); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2024 at 72.7% (266 of 366 days). Lowest qualifying Good-day share: 2021 at 58.1% (212 of 365 days).
What does AQI 46 mean for health? ▼
Rio Blanco County's median AQI of 46 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Rio Blanco County compare to other counties in Colorado? ▼
Rio Blanco County has 72.7% good air days. Nearby counties in Colorado: Adams (55.1% good), Alamosa (91.5% good), Arapahoe (58.1% good), Archuleta (83.0% good), Boulder (58.4% good), Chaffee (66.0% good).
What is the 90th percentile AQI in Rio Blanco County? ▼
The 90th percentile AQI for Rio Blanco County is 67, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 142 (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. Spotted a figure that looks wrong? Report a correction.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Rio Blanco County, Colorado · 2020–2025
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Every figure on PlainAirData 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.