Median AQI
32
Good
Alabama · County air quality · 2025
Clay County, Alabama
Median AQI 32 (Good). 85.4% of monitored days rated Good, direct from EPA Air Quality System stations.
- 32
- Median AQI
- 85.4%
- Good-air days
- 0
- Unhealthy days
- 67%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Clay County's air is good on balance, cleaner than the median US county, a median AQI of 32 with 85.4% of 239 monitored days in the Good band, driven mainly by PM2.5.
- 32
- median AQI · Good
- 85.4%
- days rated Good
- PM2.5
- main pollutant
- 67%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 133.
Data updated July 2026
- Good · 204 d · 85.4%
- Moderate · 34 d · 14.2%
- USG · 1 d · 0.4%
How did Clay County's air break down in 2025?
Across 239 monitored days, 204 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 133 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 239 days monitored. Median AQI: 32 (Good).
Insights: Clay County, Alabama. EPA monitors recorded a median Air Quality Index of 32 across 239 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 204 (85%) fell in the Good band (AQI 0–50), 34 (14%) registered Moderate readings, and 1 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 52, while the worst single-day peak hit 133 (USG). Residents averaged about 25.6 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (239 days). Across the 2020–2025 trend window, good days shifted by +121 and the median AQI moved -2 points, placing the multi-year trajectory at improving. The worst single reading over the 2020–2025 window was AQI 133, usg but never Unhealthy. Nearby counties show comparable readings: Baldwin (72.2% good, AQI 42); DeKalb (78.6% good, AQI 42); Elmore (97.2% good, AQI 32); Etowah (63.5% good, AQI 45); Jefferson (36.8% good, AQI 53); Lawrence (100.0% good, AQI 23).
Air Quality Summary
Good Days
85.4%
204 of 239 monitored days
10.4pp vs 75% target
Max AQI Recorded
133
USG
Health Grade
Good
90th-pct AQI 52
Clay County, Good days share 85.4%
National avg
Share of monitored days at AQI 0-50 (Good band).
Clay 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 239 monitored days across EPA AQI categories.
Good
204
85%
Moderate
34
14%
USG
1
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 Clay County.
- PM2.5 · 239 days · 100.0%
Health Impact Assessment
Good
Clay County's air quality is rated Good based on 85.4% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 85.4% 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 PM2.5, driving AQI on 239 of 239 monitored days.
5-Year Air Quality Trend
Air quality is improving in Clay County. Best year: 2024 (307 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 83 | 22 | 0 | 0 | 34 | 88 |
| 2021 | 87 | 23 | 0 | 0 | 36 | 70 |
| 2022 | 91 | 24 | 0 | 0 | 34 | 68 |
| 2023 | 221 | 106 | 0 | 0 | 41 | 85 |
| 2024 | 307 | 47 | 0 | 0 | 29 | 75 |
| 2025 | 204 | 34 | 1 | 0 | 32 | 133 |
How does Clay County compare?
How Clay County compares
Good-day share better than US avg
Clay County 85.4%
Baldwin County, Alabama 72.2%
US average 76.5%
Median AQI better than US avg
Clay County 32
Baldwin County, Alabama 42
US average 38
Unhealthy days / yr about average
Clay County 0
Baldwin County, Alabama 0
US average 0
Other Counties in Alabama
Air quality comparison for nearby counties in Alabama.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Clay County.
Archuleta County, Colorado
AQI 32 · 79.5% 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 Clay County's air means for you
The air here stays in the breathable range year-round, with PM2.5 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 32 means for exposure. Health guidance
- See how Clay County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Clay County with its Alabama neighbours before drawing a conclusion about the region. All of Alabama
Based on 239 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 Clay County, Alabama? ▼
Clay County has a median Air Quality Index (AQI) of 32, rated "Good." 85.4% of monitored days (204 out of 239) had good air quality in 2025.
What is the main pollutant in Clay County? ▼
The primary pollutant in Clay County is Fine Particles (PM2.5), which was the main AQI driver on 239 days (100% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Clay County have? ▼
In 2025, Clay County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 133.
Is the air quality in Clay County getting better or worse? ▼
Air quality in Clay County is improving based on 5-year trends (2020-2025). Best year: 2024 with 307 good days. Worst year: 2020 with 83 good days.
What does AQI 32 mean for health? ▼
Clay 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 Clay County compare to other counties in Alabama? ▼
Clay County has 85.4% good air days. Nearby counties in Alabama: Baldwin (72.2% good), DeKalb (78.6% good), Elmore (97.2% good), Etowah (63.5% good), Jefferson (36.8% good), Lawrence (100.0% good).
What is the 90th percentile AQI in Clay County? ▼
The 90th percentile AQI for Clay County is 52, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 133 (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.