Median AQI
42
Good
Nebraska · County air quality · 2025
Douglas County, Nebraska
Median AQI 42 (Good). 71.0% of monitored days rated Good, direct from EPA Air Quality System stations.
- 42
- Median AQI
- 71.0%
- Good-air days
- 0
- Unhealthy days
- 34%
- Cleaner than US counties
Douglas County's 2025 annual median AQI is 42 (Good), with 71.0% Good days
According to the U.S. EPA Air Quality System, Douglas County, Nebraska posted a 2025 median AQI of 42 (Good) across 365 monitored days, with 71.0% 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
- Douglas County's 71.0% Good-day share places it cleaner than 34% of US counties in 2025.
- Closest median-AQI peer
- Ada County (74.0% Good, median AQI 42) is the closest nationwide median-AQI peer to Douglas County.
- 2020–2025 trend
- Douglas County's floor-qualifying Good-day share is stable from 2020 to 2025 (73.0% → 71.0%).
- Median AQI
- Median AQI: 42
The verdict
According to EPA Air Quality System monitoring data, Douglas County's air is good on balance, more polluted than the median US county, a median AQI of 42 with 71.0% of 365 monitored days in the Good band, driven mainly by Ozone.
- 42
- median AQI · Good
- 71.0%
- days rated Good
- Ozone
- main pollutant
- 34%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 137.
Annual release change
What changed in the 2025 EPA annual release
- Douglas County's Good-day share rose from 63.7% to 71.0% between the 2024 and 2025 EPA annual releases, a change of +7.3 percentage points.
- Douglas County's peak single-day AQI rose from 101 to 137 between the 2024 and 2025 EPA annual releases, a change of +36 points.
- Douglas County's median AQI fell from 45 to 42 between the 2024 and 2025 EPA annual releases, a change of -3 points.
Data updated August 2026
- Good · 259 d · 71.0%
- Moderate · 104 d · 28.5%
- USG · 2 d · 0.5%
How did Douglas County's air break down in 2025?
Across 365 monitored days, 259 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 137 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 365 days monitored. Median AQI: 42 (Good).
Insights: Douglas County, Nebraska. EPA monitors recorded a median Air Quality Index of 42 across 365 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 259 (71%) fell in the Good band (AQI 0–50), 104 (28%) registered Moderate readings, and 2 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 62, while the worst single-day peak hit 137 (USG). Residents averaged about 21.3 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (176 days), PM2.5 (167 days), PM10 (22 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -2.0 points and the median AQI moved +0 points, placing the multi-year trajectory at stable. The worst single reading over the 2020–2025 window was AQI 137, usg but never Unhealthy. Nearby counties show comparable readings: Cass (95.9% good, AQI 19); Gage (75.8% good, AQI 34); Hall (82.5% good, AQI 34); Knox (92.0% good, AQI 36); Lancaster (85.4% good, AQI 37); Sarpy (78.8% good, AQI 32).
Air Quality Summary
Good Days
71.0%
259 of 365 monitored days
-4.0pp vs 75% target
Max AQI Recorded
137
USG
Health Grade
Moderate
90th-pct AQI 62
Douglas County, Good days share 71.0%
National avg
Share of monitored days at AQI 0-50 (Good band).
Douglas 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 365 monitored days across EPA AQI categories.
Good
259
71%
Moderate
104
28%
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 Douglas County.
- Ozone · 176 days · 48.2%
- PM2.5 · 167 days · 45.8%
- PM10 · 22 days · 6.0%
Health Impact Assessment
Moderate
Douglas County's air quality is rated Moderate based on 71.0% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 71.0% 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 176 of 365 monitored days.
5-Year Air Quality Trend
Air quality is stable in Douglas County. Highest Good-day share: 2022 (76.2%, 278 of 365 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 267 | 97 | 1 | 1 | 42 | 157 |
| 2021 | 244 | 116 | 5 | 0 | 43 | 150 |
| 2022 | 278 | 86 | 1 | 0 | 41 | 108 |
| 2023 | 211 | 130 | 22 | 2 | 45 | 169 |
| 2024 | 233 | 132 | 1 | 0 | 45 | 101 |
| 2025 | 259 | 104 | 2 | 0 | 42 | 137 |
How does Douglas County compare?
How Douglas County compares
Good-day share worse than typical
Douglas County 71.0%
Ada County, Idaho 74.0%
Typical US county 76.0%
Median AQI worse than typical
Douglas County 42
Ada County, Idaho 42
Typical US county 39
Unhealthy days / yr better than typical
Douglas County 0
Ada County, Idaho 0
Typical US county 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Douglas County (42), not geographic neighbors.
Ada County, Idaho
Median AQI 42 · 74.0% Good-day share
Adams County, Pennsylvania
Median AQI 42 · 74.4% Good-day share
Allen County, Ohio
Median AQI 42 · 67.0% Good-day share
Asotin County, Washington
Median AQI 42 · 61.9% Good-day share
Baldwin County, Alabama
Median AQI 42 · 75.5% Good-day share
Bell County, Kentucky
Median AQI 42 · 67.0% Good-day share
Same primary pollutant: Ozone
Ozone 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).
Bergen County, New Jersey
71.1% Good-day share · median AQI 40
Madison County, Indiana
71.2% Good-day share · median AQI 41
Chester County, Pennsylvania
71.3% Good-day share · median AQI 43
Armstrong County, Pennsylvania
70.5% Good-day share · median AQI 41
Blount County, Tennessee
71.5% Good-day share · median AQI 44
Lewis and Clark County, Montana
71.5% Good-day share · median AQI 44
Nebraska counties on the map
Geographic containment only, other monitored counties in Nebraska, independent of AQI or pollutant match.
What Douglas 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 Douglas County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Douglas County with its Nebraska neighbours before drawing a conclusion about the region. All of Nebraska
Based on 365 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 Douglas County, Nebraska? ▼
Douglas County has a median Air Quality Index (AQI) of 42, rated "Good." 71.0% of monitored days (259 out of 365) had good air quality in 2025.
What is the main pollutant in Douglas County? ▼
The primary pollutant in Douglas County is Ozone (O3), which was the main AQI driver on 176 days (48% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Douglas County have? ▼
In 2025, Douglas County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 137.
Is the air quality in Douglas County getting better or worse? ▼
Air quality in Douglas County is stable across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2022 at 76.2% (278 of 365 days). Lowest qualifying Good-day share: 2023 at 57.8% (211 of 365 days).
What does AQI 42 mean for health? ▼
Douglas County's median AQI of 42 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Douglas County compare to other counties in Nebraska? ▼
Douglas County has 71.0% good air days. Nearby counties in Nebraska: Cass (95.9% good), Gage (75.8% good), Hall (82.5% good), Knox (92.0% good), Lancaster (85.4% good), Sarpy (78.8% good).
What is the 90th percentile AQI in Douglas County? ▼
The 90th percentile AQI for Douglas County is 62, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 137 (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. Spotted a figure that looks wrong? Report a correction.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Douglas County, Nebraska · 2020–2025
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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.