Median AQI
42
Good
Missouri · County air quality · 2025
Sainte Genevieve County, Missouri
Median AQI 42 (Good). 93.9% of monitored days rated Good, direct from EPA Air Quality System stations.
- 42
- Median AQI
- 93.9%
- Good-air days
- 0
- Unhealthy days
- 85%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Sainte Genevieve County's air is good on balance, cleaner than most US counties, a median AQI of 42 with 93.9% of 99 monitored days in the Good band, driven mainly by Ozone.
- 42
- median AQI · Good
- 93.9%
- days rated Good
- Ozone
- main pollutant
- 85%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 71.
Data updated July 2026
- Good · 93 d · 93.9%
- Moderate · 6 d · 6.1%
How did Sainte Genevieve County's air break down in 2025?
Across 99 monitored days, 93 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 71 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 99 days monitored. Median AQI: 42 (Good).
Insights: Sainte Genevieve County, Missouri. EPA monitors recorded a median Air Quality Index of 42 across 99 measured days in 2025, earning a Good classification and a Excellent health grade. Of those days, 93 (94%) fell in the Good band (AQI 0–50), 6 (6%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 49, while the worst single-day peak hit 71 (Moderate). Residents averaged about 28.2 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (99 days). Across the 2020–2025 trend window, good days shifted by -136 and the median AQI moved +6 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 71, moderate but never Unhealthy. 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
93.9%
93 of 99 monitored days
18.9pp vs 75% target
Max AQI Recorded
71
Moderate
Health Grade
Excellent
90th-pct AQI 49
Sainte Genevieve County, Good days share 93.9%
National avg
Share of monitored days at AQI 0-50 (Good band).
Sainte Genevieve 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 99 monitored days across EPA AQI categories.
Good
93
94%
Moderate
6
6%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Sainte Genevieve County.
- Ozone · 99 days · 100.0%
Health Impact Assessment
Excellent
Sainte Genevieve County's air quality is rated Excellent based on 93.9% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 93.9% of monitored days in 2025, with a median AQI of 42. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 99 of 99 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Sainte Genevieve County. Best year: 2020 (229 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 229 | 16 | 0 | 0 | 36 | 87 |
| 2021 | 227 | 18 | 0 | 0 | 39 | 100 |
| 2022 | 215 | 29 | 0 | 0 | 41 | 100 |
| 2023 | 195 | 38 | 12 | 0 | 44 | 147 |
| 2024 | 225 | 23 | 0 | 0 | 43 | 100 |
| 2025 | 93 | 6 | 0 | 0 | 42 | 71 |
How does Sainte Genevieve County compare?
How Sainte Genevieve County compares
Good-day share better than US avg
Sainte Genevieve County 93.9%
Andrew County, Missouri 84.3%
US average 76.5%
Median AQI worse than US avg
Sainte Genevieve County 42
Andrew County, Missouri 42
US average 38
Unhealthy days / yr about average
Sainte Genevieve County 0
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 Sainte Genevieve County.
Adams County, Pennsylvania
AQI 42 · 73.8% good
Anderson County, Tennessee
AQI 42 · 91.0% good
Andrew County, Missouri
AQI 42 · 84.3% good
Armstrong County, Pennsylvania
AQI 42 · 68.1% good
Baldwin County, Alabama
AQI 42 · 72.2% good
Belmont County, Ohio
AQI 42 · 63.0% good
What Sainte Genevieve 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 42 means for exposure. Health guidance
- See how Sainte Genevieve County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Sainte Genevieve County with its Missouri neighbours before drawing a conclusion about the region. All of Missouri
Based on 99 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 Sainte Genevieve County, Missouri? ▼
Sainte Genevieve County has a median Air Quality Index (AQI) of 42, rated "Good." 93.9% of monitored days (93 out of 99) had good air quality in 2025.
What is the main pollutant in Sainte Genevieve County? ▼
The primary pollutant in Sainte Genevieve County is Ozone (O3), which was the main AQI driver on 99 days (100% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Sainte Genevieve County have? ▼
In 2025, Sainte Genevieve County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 71.
Is the air quality in Sainte Genevieve County getting better or worse? ▼
Air quality in Sainte Genevieve County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 229 good days. Worst year: 2025 with 93 good days.
What does AQI 42 mean for health? ▼
Sainte Genevieve County's median AQI of 42 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 Sainte Genevieve County compare to other counties in Missouri? ▼
Sainte Genevieve County has 93.9% 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 Sainte Genevieve County? ▼
The 90th percentile AQI for Sainte Genevieve County is 49, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 71 (Moderate).
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.