Median AQI
27
Good
New York · County air quality · 2025
Oneida County, New York
Median AQI 27 (Good). 84.4% of monitored days rated Good, direct from EPA Air Quality System stations.
- 27
- Median AQI
- 84.4%
- Good-air days
- 0
- Unhealthy days
- 68%
- Cleaner than US counties
Oneida County's 2025 annual median AQI is 27 (Good), with 84.4% Good days
According to the U.S. EPA Air Quality System, Oneida County, New York posted a 2025 median AQI of 27 (Good) across 353 monitored days, with 84.4% rated Good and 0 unhealthy or worse. This is an annual comparison, not today's advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US
- Oneida County's 84.4% Good-day share places it cleaner than 68% of US counties in 2025.
- Closest median-AQI peer
- Brown County (83.6% Good, median AQI 27) is the closest nationwide median-AQI peer to Oneida County.
- 2020–2025 trend
- Oneida County's floor-qualifying Good-day share is worsening from 2020 to 2025 (92.8% → 84.4%).
- Median AQI
- Median AQI: 27
The verdict
According to EPA Air Quality System monitoring data, Oneida County's air is good on balance, cleaner than the median US county, a median AQI of 27 with 84.4% of 353 monitored days in the Good band, driven mainly by PM2.5.
- 27
- median AQI · Good
- 84.4%
- days rated Good
- PM2.5
- main pollutant
- 68%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 99.
Annual release change
What changed in the 2025 EPA annual release
- Oneida County's peak single-day AQI rose from 68 to 99 between the 2024 and 2025 EPA annual releases, a change of +31 points.
- Oneida County's Good-day share fell from 86.0% to 84.4% between the 2024 and 2025 EPA annual releases, a change of -1.5 percentage points.
Data updated August 2026
- Good · 298 d · 84.4%
- Moderate · 55 d · 15.6%
How did Oneida County's air break down in 2025?
Across 353 monitored days, 298 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 99 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 353 days monitored. Median AQI: 27 (Good).
Insights: Oneida County, New York. EPA monitors recorded a median Air Quality Index of 27 across 353 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 298 (84%) fell in the Good band (AQI 0–50), 55 (16%) 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 99 (Moderate). Residents averaged about 25.3 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (353 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -8.4 points 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 99, moderate but never Unhealthy. Nearby counties show comparable readings: Albany (68.5% good, AQI 39); Bronx (59.2% good, AQI 45); Chautauqua (89.0% good, AQI 36); Dutchess (94.0% good, AQI 34); Erie (63.8% good, AQI 44); Essex (83.8% good, AQI 41).
Air Quality Summary
Good Days
84.4%
298 of 353 monitored days
9.4pp vs 75% target
Max AQI Recorded
99
Moderate
Health Grade
Good
90th-pct AQI 54
Oneida County, Good days share 84.4%
National avg
Share of monitored days at AQI 0-50 (Good band).
Oneida 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 353 monitored days across EPA AQI categories.
Good
298
84%
Moderate
55
16%
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 Oneida County.
- PM2.5 · 353 days · 100.0%
Health Impact Assessment
Good
Oneida County's air quality is rated Good based on 84.4% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 84.4% of monitored days in 2025, with a median AQI of 27. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 353 of 353 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Oneida County. Highest Good-day share: 2020 (92.8%, 324 of 349 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 324 | 25 | 0 | 0 | 21 | 81 |
| 2021 | 311 | 35 | 1 | 0 | 25 | 107 |
| 2022 | 288 | 44 | 0 | 0 | 26 | 83 |
| 2023 | 275 | 70 | 3 | 3 | 32 | 190 |
| 2024 | 300 | 49 | 0 | 0 | 27 | 68 |
| 2025 | 298 | 55 | 0 | 0 | 27 | 99 |
How does Oneida County compare?
How Oneida County compares
Good-day share better than typical
Oneida County 84.4%
Brown County, South Dakota 83.6%
Typical US county 76.0%
Median AQI better than typical
Oneida County 27
Brown County, South Dakota 27
Typical US county 39
Unhealthy days / yr better than typical
Oneida County 0
Brown County, South Dakota 0
Typical US county 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Oneida County (27), not geographic neighbors.
Brown County, South Dakota
Median AQI 27 · 83.6% Good-day share
Columbia County, Oregon
Median AQI 27 · 92.9% Good-day share
Linn County, Oregon
Median AQI 27 · 80.0% Good-day share
Orange County, New York
Median AQI 27 · 86.9% Good-day share
Prowers County, Colorado
Median AQI 27 · 92.6% Good-day share
Sheridan County, Wyoming
Median AQI 27 · 89.1% Good-day share
Same primary pollutant: PM2.5
PM2.5 led the AQI on the most monitored days here. These peers share that driver and the closest Good-day share (a second relationship type beyond median-AQI neighbors).
Union County, Oregon
84.4% Good-day share · median AQI 27
Edgecombe County, North Carolina
84.4% Good-day share · median AQI 38
Juneau County, Alaska
84.3% Good-day share · median AQI 23
Silver Bow County, Montana
84.9% Good-day share · median AQI 28
Roanoke County, Virginia
83.8% Good-day share · median AQI 37
Montgomery County, Tennessee
83.8% Good-day share · median AQI 32
New York counties on the map
Geographic containment only, other monitored counties in New York, independent of AQI or pollutant match.
What Oneida 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 27 means for exposure. Health guidance
- See how Oneida County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Oneida County with its New York neighbours before drawing a conclusion about the region. All of New York
Based on 353 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
Keep exploring the annual AQI record
Air-quality reading list
Frequently Asked Questions
What is the air quality in Oneida County, New York? ▼
Oneida County has a median Air Quality Index (AQI) of 27, rated "Good." 84.4% of monitored days (298 out of 353) had good air quality in 2025.
What is the main pollutant in Oneida County? ▼
The primary pollutant in Oneida County is Fine Particles (PM2.5), which was the main AQI driver on 353 days (100% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Oneida County have? ▼
In 2025, Oneida County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 99.
Is the air quality in Oneida County getting better or worse? ▼
Air quality in Oneida County is worsening across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2020 at 92.8% (324 of 349 days). Lowest qualifying Good-day share: 2023 at 78.3% (275 of 351 days).
What does AQI 27 mean for health? ▼
Oneida County's median AQI of 27 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Oneida County compare to other counties in New York? ▼
Oneida County has 84.4% good air days. Nearby counties in New York: Albany (68.5% good), Bronx (59.2% good), Chautauqua (89.0% good), Dutchess (94.0% good), Erie (63.8% good), Essex (83.8% good).
What is the 90th percentile AQI in Oneida County? ▼
The 90th percentile AQI for Oneida County is 54, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 99 (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. Spotted a figure that looks wrong? Report a correction.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Oneida County, New York · 2020–2025
Share this annual record
Send the source-year summary or download its ready-to-use data card.
Download this county's annual AQI row as CSV , with the same EPA fields and denominator shown on this page.
Every figure on PlainAirData 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.