Median AQI
44
Good
Missouri · County air quality · 2025
Greene County, Missouri
Median AQI 44 (Good). 71.4% of monitored days rated Good, direct from EPA Air Quality System stations.
- 44
- Median AQI
- 71.4%
- Good-air days
- 1
- Unhealthy days
- 34%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Greene County's air is good on balance, more polluted than the median US county, a median AQI of 44 with 71.4% of 147 monitored days in the Good band, driven mainly by PM2.5.
- 44
- median AQI · Good
- 71.4%
- days rated Good
- PM2.5
- main pollutant
- 34%
- cleaner than US counties
1 day reached Unhealthy or worse; the worst single reading hit AQI 160.
Data updated July 2026
- Good · 105 d · 71.4%
- Moderate · 40 d · 27.2%
- USG · 1 d · 0.7%
- Unhealthy · 1 d · 0.7%
How did Greene County's air break down in 2025?
Across 147 monitored days, 105 fell in the Good band (AQI 0–50) and 1 reached Unhealthy or worse. The worst single day peaked at AQI 160 (Unhealthy).
EPA AQS →Air quality data from EPA Air Quality System (2025). 147 days monitored. Median AQI: 44 (Good).
Insights: Greene County, Missouri. EPA monitors recorded a median Air Quality Index of 44 across 147 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 105 (71%) fell in the Good band (AQI 0–50), 40 (27%) registered Moderate readings, and 1 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 61, while the worst single-day peak hit 160 (Unhealthy). Residents averaged about 21.4 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (82 days), Ozone (62 days), PM10 (3 days). Across the 2020–2025 trend window, good days shifted by -163 and the median AQI moved +4 points, placing the multi-year trajectory at stable. Residents and visitors experienced 1 unhealthy-or-worse days combined, periods when the EPA recommends sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Andrew (84.3% good, AQI 42); Boone (89.1% good, AQI 41); Buchanan (64.2% good, AQI 39); Callaway (85.6% good, AQI 42); Cass (82.2% good, AQI 41); Cedar (81.8% good, AQI 40).
Air Quality Summary
Good Days
71.4%
105 of 147 monitored days
-3.6pp vs 75% target
Max AQI Recorded
160
Unhealthy
Health Grade
Moderate
90th-pct AQI 61
Greene County, Good days share 71.4%
National avg
Share of monitored days at AQI 0-50 (Good band).
Greene County, Unhealthy-or-worse share 0.7%
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 147 monitored days across EPA AQI categories.
Good
105
71%
Moderate
40
27%
USG
1
1%
Unhealthy
1
1%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Greene County.
- PM2.5 · 82 days · 55.8%
- Ozone · 62 days · 42.2%
- PM10 · 3 days · 2.0%
Health Impact Assessment
Moderate
Greene County's air quality is rated Moderate based on 71.4% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.
Air quality is acceptable most days, but 1 days reached "Unhealthy for Sensitive Groups" (AQI 101-150) and peak AQI reached 160. Sensitive groups should monitor real-time conditions at AirNow.gov.
The dominant pollutant is PM2.5, driving AQI on 82 of 147 monitored days.
5-Year Air Quality Trend
Air quality is stable in Greene County. Best year: 2021 (300 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 268 | 95 | 1 | 0 | 40 | 116 |
| 2021 | 300 | 65 | 0 | 0 | 38 | 84 |
| 2022 | 202 | 163 | 0 | 0 | 49 | 100 |
| 2023 | 188 | 171 | 6 | 0 | 49 | 122 |
| 2024 | 227 | 133 | 0 | 0 | 45 | 90 |
| 2025 | 105 | 40 | 1 | 1 | 44 | 160 |
How does Greene County compare?
How Greene County compares
Good-day share worse than US avg
Greene County 71.4%
Andrew County, Missouri 84.3%
US average 76.5%
Median AQI worse than US avg
Greene County 44
Andrew County, Missouri 42
US average 38
Unhealthy days / yr worse than US avg
Greene County 1
Andrew County, Missouri 0
US average 0
Other Counties in Missouri
Air quality comparison for nearby counties in Missouri.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Greene County.
Baltimore County, Maryland
AQI 44 · 70.4% good
Baltimore (City) County, Maryland
AQI 44 · 68.7% good
Bartholomew County, Indiana
AQI 44 · 69.2% good
Berks County, Pennsylvania
AQI 44 · 65.6% good
Bolivar County, Mississippi
AQI 44 · 70.3% good
Brewster County, Texas
AQI 44 · 69.0% good
What Greene County's air means for you
On most days the air here is fine, but PM2.5 drives 1 unhealthy-or-worse day a year that sensitive groups should plan around.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 44 means for exposure. Health guidance
- See how Greene County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Greene County with its Missouri neighbours before drawing a conclusion about the region. All of Missouri
Based on 147 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 Greene County, Missouri? ▼
Greene County has a median Air Quality Index (AQI) of 44, rated "Good." 71.4% of monitored days (105 out of 147) had good air quality in 2025.
What is the main pollutant in Greene County? ▼
The primary pollutant in Greene County is Fine Particles (PM2.5), which was the main AQI driver on 82 days (56% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Greene County have? ▼
In 2025, Greene County recorded 1 unhealthy air days (1 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 160.
Is the air quality in Greene County getting better or worse? ▼
Air quality in Greene County is stable based on 5-year trends (2020-2025). Best year: 2021 with 300 good days. Worst year: 2025 with 105 good days.
What does AQI 44 mean for health? ▼
Greene County's median AQI of 44 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 Greene County compare to other counties in Missouri? ▼
Greene County has 71.4% good air days. Nearby counties in Missouri: Andrew (84.3% good), Boone (89.1% good), Buchanan (64.2% good), Callaway (85.6% good), Cass (82.2% good), Cedar (81.8% good).
What is the 90th percentile AQI in Greene County? ▼
The 90th percentile AQI for Greene County is 61, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 160 (Unhealthy).
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.