Median AQI
43
Good
New Jersey · County air quality · 2025
Gloucester County, New Jersey
Median AQI 43 (Good). 72.4% of monitored days rated Good, direct from EPA Air Quality System stations.
- 43
- Median AQI
- 72.4%
- Good-air days
- 0
- Unhealthy days
- 36%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Gloucester County's air is good on balance, more polluted than the median US county, a median AQI of 43 with 72.4% of 174 monitored days in the Good band, driven mainly by Ozone.
- 43
- median AQI · Good
- 72.4%
- days rated Good
- Ozone
- main pollutant
- 36%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 143.
Data updated July 2026
- Good · 126 d · 72.4%
- Moderate · 46 d · 26.4%
- USG · 2 d · 1.1%
How did Gloucester County's air break down in 2025?
Across 174 monitored days, 126 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 143 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 174 days monitored. Median AQI: 43 (Good).
Insights: Gloucester County, New Jersey. EPA monitors recorded a median Air Quality Index of 43 across 174 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 126 (72%) fell in the Good band (AQI 0–50), 46 (26%) registered Moderate readings, and 2 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 65, while the worst single-day peak hit 143 (USG). Residents averaged about 21.7 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (98 days), PM2.5 (76 days). Across the 2020–2025 trend window, good days shifted by -97 and the median AQI moved +5 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 143, usg but never Unhealthy. Nearby counties show comparable readings: Atlantic (79.6% good, AQI 38); Bergen (71.1% good, AQI 40); Camden (69.4% good, AQI 44); Cumberland (73.0% good, AQI 42); Hudson (74.7% good, AQI 41); Hunterdon (73.6% good, AQI 41).
Air Quality Summary
Good Days
72.4%
126 of 174 monitored days
-2.6pp vs 75% target
Max AQI Recorded
143
USG
Health Grade
Moderate
90th-pct AQI 65
Gloucester County, Good days share 72.4%
National avg
Share of monitored days at AQI 0-50 (Good band).
Gloucester 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 174 monitored days across EPA AQI categories.
Good
126
72%
Moderate
46
26%
USG
2
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 Gloucester County.
- Ozone · 98 days · 56.3%
- PM2.5 · 76 days · 43.7%
Health Impact Assessment
Moderate
Gloucester County's air quality is rated Moderate based on 72.4% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 72.4% of monitored days in 2025, with a median AQI of 43. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 98 of 174 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Gloucester County. Best year: 2024 (265 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 223 | 29 | 1 | 0 | 38 | 101 |
| 2021 | 238 | 57 | 2 | 0 | 40 | 101 |
| 2022 | 217 | 68 | 3 | 0 | 42 | 126 |
| 2023 | 236 | 77 | 5 | 3 | 43 | 185 |
| 2024 | 265 | 92 | 8 | 0 | 41 | 129 |
| 2025 | 126 | 46 | 2 | 0 | 43 | 143 |
How does Gloucester County compare?
How Gloucester County compares
Good-day share worse than US avg
Gloucester County 72.4%
Atlantic County, New Jersey 79.6%
US average 76.5%
Median AQI worse than US avg
Gloucester County 43
Atlantic County, New Jersey 38
US average 38
Unhealthy days / yr about average
Gloucester County 0
Atlantic County, New Jersey 0
US average 0
Other Counties in New Jersey
Air quality comparison for nearby counties in New Jersey.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Gloucester County.
Allegan County, Michigan
AQI 43 · 71.2% good
Allen County, Ohio
AQI 43 · 65.9% good
Ashtabula County, Ohio
AQI 43 · 81.2% good
Bell County, Kentucky
AQI 43 · 63.5% good
Boise County, Idaho
AQI 43 · 72.9% good
Brazos County, Texas
AQI 43 · 63.4% good
What Gloucester 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 43 means for exposure. Health guidance
- See how Gloucester County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Gloucester County with its New Jersey neighbours before drawing a conclusion about the region. All of New Jersey
Based on 174 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 Gloucester County, New Jersey? ▼
Gloucester County has a median Air Quality Index (AQI) of 43, rated "Good." 72.4% of monitored days (126 out of 174) had good air quality in 2025.
What is the main pollutant in Gloucester County? ▼
The primary pollutant in Gloucester County is Ozone (O3), which was the main AQI driver on 98 days (56% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Gloucester County have? ▼
In 2025, Gloucester County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 143.
Is the air quality in Gloucester County getting better or worse? ▼
Air quality in Gloucester County is worsening based on 5-year trends (2020-2025). Best year: 2024 with 265 good days. Worst year: 2025 with 126 good days.
What does AQI 43 mean for health? ▼
Gloucester County's median AQI of 43 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 Gloucester County compare to other counties in New Jersey? ▼
Gloucester County has 72.4% good air days. Nearby counties in New Jersey: Atlantic (79.6% good), Bergen (71.1% good), Camden (69.4% good), Cumberland (73.0% good), Hudson (74.7% good), Hunterdon (73.6% good).
What is the 90th percentile AQI in Gloucester County? ▼
The 90th percentile AQI for Gloucester County is 65, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 143 (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.