Median AQI
39
Good
Georgia · County air quality · 2025
Glynn County, Georgia
Median AQI 39 (Good). 81.9% of monitored days rated Good, direct from EPA Air Quality System stations.
- 39
- Median AQI
- 81.9%
- Good-air days
- 0
- Unhealthy days
- 57%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Glynn County's air is good on balance, cleaner than the median US county, a median AQI of 39 with 81.9% of 287 monitored days in the Good band, driven mainly by PM2.5.
- 39
- median AQI · Good
- 81.9%
- days rated Good
- PM2.5
- main pollutant
- 57%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 94.
Data updated July 2026
- Good · 235 d · 81.9%
- Moderate · 52 d · 18.1%
How did Glynn County's air break down in 2025?
Across 287 monitored days, 235 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 94 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 287 days monitored. Median AQI: 39 (Good).
Insights: Glynn County, Georgia. EPA monitors recorded a median Air Quality Index of 39 across 287 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 235 (82%) fell in the Good band (AQI 0–50), 52 (18%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 54, while the worst single-day peak hit 94 (Moderate). Residents averaged about 24.6 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (145 days), Ozone (142 days). Across the 2020–2025 trend window, good days shifted by -21 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 94, moderate but never Unhealthy. Nearby counties show comparable readings: Bibb (49.5% good, AQI 51); Charlton (79.0% good, AQI 24); Chatham (66.7% good, AQI 44); Clarke (66.7% good, AQI 44); Clayton (53.1% good, AQI 49); Cobb (92.5% good, AQI 36).
Air Quality Summary
Good Days
81.9%
235 of 287 monitored days
6.9pp vs 75% target
Max AQI Recorded
94
Moderate
Health Grade
Good
90th-pct AQI 54
Glynn County, Good days share 81.9%
National avg
Share of monitored days at AQI 0-50 (Good band).
Glynn 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 287 monitored days across EPA AQI categories.
Good
235
82%
Moderate
52
18%
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 Glynn County.
- PM2.5 · 145 days · 50.5%
- Ozone · 142 days · 49.5%
Health Impact Assessment
Good
Glynn County's air quality is rated Good based on 81.9% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 81.9% of monitored days in 2025, with a median AQI of 39. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 145 of 287 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Glynn County. Best year: 2024 (286 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 256 | 29 | 0 | 0 | 33 | 97 |
| 2021 | 267 | 55 | 0 | 0 | 38 | 80 |
| 2022 | 221 | 134 | 1 | 0 | 45 | 106 |
| 2023 | 243 | 120 | 0 | 0 | 43 | 90 |
| 2024 | 286 | 80 | 0 | 0 | 39 | 84 |
| 2025 | 235 | 52 | 0 | 0 | 39 | 94 |
How does Glynn County compare?
How Glynn County compares
Good-day share better than US avg
Glynn County 81.9%
Bibb County, Georgia 49.5%
US average 76.5%
Median AQI worse than US avg
Glynn County 39
Bibb County, Georgia 51
US average 38
Unhealthy days / yr about average
Glynn County 0
Bibb County, Georgia 0
US average 0
Other Counties in Georgia
Air quality comparison for nearby counties in Georgia.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Glynn County.
Ada County, Idaho
AQI 39 · 80.6% good
Aiken County, South Carolina
AQI 39 · 89.1% good
Albany County, New York
AQI 39 · 67.4% good
Alexander County, North Carolina
AQI 39 · 92.4% good
Ashland County, Wisconsin
AQI 39 · 85.6% good
Bennington County, Vermont
AQI 39 · 82.9% good
What Glynn 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 39 means for exposure. Health guidance
- See how Glynn County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Glynn County with its Georgia neighbours before drawing a conclusion about the region. All of Georgia
Based on 287 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 Glynn County, Georgia? ▼
Glynn County has a median Air Quality Index (AQI) of 39, rated "Good." 81.9% of monitored days (235 out of 287) had good air quality in 2025.
What is the main pollutant in Glynn County? ▼
The primary pollutant in Glynn County is Fine Particles (PM2.5), which was the main AQI driver on 145 days (51% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Glynn County have? ▼
In 2025, Glynn County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 94.
Is the air quality in Glynn County getting better or worse? ▼
Air quality in Glynn County is worsening based on 5-year trends (2020-2025). Best year: 2024 with 286 good days. Worst year: 2022 with 221 good days.
What does AQI 39 mean for health? ▼
Glynn County's median AQI of 39 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 Glynn County compare to other counties in Georgia? ▼
Glynn County has 81.9% good air days. Nearby counties in Georgia: Bibb (49.5% good), Charlton (79.0% good), Chatham (66.7% good), Clarke (66.7% good), Clayton (53.1% good), Cobb (92.5% good).
What is the 90th percentile AQI in Glynn County? ▼
The 90th percentile AQI for Glynn County is 54, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 94 (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.