Median AQI
39
Good
North Dakota · County air quality · 2025
Burleigh County, North Dakota
Median AQI 39 (Good). 78.1% of monitored days rated Good, direct from EPA Air Quality System stations.
- 39
- Median AQI
- 78.1%
- Good-air days
- 4
- Unhealthy days
- 51%
- Cleaner than US counties
Burleigh County's 2025 annual median AQI is 39 (Good), with 78.1% Good days
According to the U.S. EPA Air Quality System, Burleigh County, North Dakota posted a 2025 median AQI of 39 (Good) across 365 monitored days, with 78.1% rated Good and 4 unhealthy or worse. This is an annual comparison, not today's advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US
- Burleigh County's 78.1% Good-day share places it cleaner than 51% of US counties in 2025.
- Closest median-AQI peer
- Aiken County (90.6% Good, median AQI 39) is the closest nationwide median-AQI peer to Burleigh County.
- 2020–2025 trend
- Burleigh County's floor-qualifying Good-day share is worsening from 2020 to 2025 (82.5% → 78.3%).
- Median AQI
- Median AQI: 39
The verdict
According to EPA Air Quality System monitoring data, Burleigh County's air is good on balance, cleaner than the median US county, a median AQI of 39 with 78.1% of 365 monitored days in the Good band, driven mainly by Ozone.
- 39
- median AQI · Good
- 78.1%
- days rated Good
- Ozone
- main pollutant
- 51%
- cleaner than US counties
4 days reached Unhealthy or worse; the worst single reading hit AQI 218.
Annual release change
What changed in the 2025 EPA annual release
- Burleigh County's Good-day share rose from 73.2% to 78.1% between the 2024 and 2025 EPA annual releases, a change of +4.9 percentage points.
- Burleigh County's peak single-day AQI rose from 174 to 218 between the 2024 and 2025 EPA annual releases, a change of +44 points.
- Burleigh County's Unhealthy-category days rose from 1 to 3 between the 2024 and 2025 EPA annual releases, a change of +2 days.
Data updated August 2026
- Good · 285 d · 78.1%
- Moderate · 68 d · 18.6%
- USG · 8 d · 2.2%
- Unhealthy · 3 d · 0.8%
- Very Unhealthy · 1 d · 0.3%
How did Burleigh County's air break down in 2025?
Across 365 monitored days, 285 fell in the Good band (AQI 0–50) and 4 reached Unhealthy or worse. The worst single day peaked at AQI 218 (Very Unhealthy).
EPA AQS →Air quality data from EPA Air Quality System (2025). 365 days monitored. Median AQI: 39 (Good).
Insights: Burleigh County, North Dakota. EPA monitors recorded a median Air Quality Index of 39 across 365 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 285 (78%) fell in the Good band (AQI 0–50), 68 (19%) registered Moderate readings, and 8 (2%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 60, while the worst single-day peak hit 218 (Very Unhealthy). Residents averaged about 23.4 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (220 days), PM2.5 (137 days), PM10 (5 days), NO2 (3 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -4.4 points and the median AQI moved +2 points, placing the multi-year trajectory at worsening. The annual record contains 4 days at Unhealthy or worse. On those days, the EPA recommends that sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Billings (82.7% good, AQI 38); Burke (76.2% good, AQI 38); Cass (76.2% good, AQI 37); Dunn (79.7% good, AQI 39); McKenzie (80.8% good, AQI 39); Mercer (80.3% good, AQI 37).
Air Quality Summary
Good Days
78.1%
285 of 365 monitored days
3.1pp vs 75% target
Max AQI Recorded
218
Very Unhealthy
Health Grade
Good
90th-pct AQI 60
Burleigh County, Good days share 78.1%
National avg
Share of monitored days at AQI 0-50 (Good band).
Burleigh County, Unhealthy-or-worse share 11.0%
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
285
78%
Moderate
68
19%
USG
8
2%
Unhealthy
3
1%
Very Unhealthy
1
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Burleigh County.
- Ozone · 220 days · 60.3%
- PM2.5 · 137 days · 37.5%
- PM10 · 5 days · 1.4%
- NO₂ · 3 days · 0.8%
Health Impact Assessment
Good
Burleigh County's air quality is rated Good based on 78.1% good air days. There were 4 unhealthy days in 2025 when outdoor activity should be limited.
Air quality reached unhealthy levels on 4 days in 2025 (3 Unhealthy, 1 Very Unhealthy). Sensitive groups, including people with asthma, COPD, cardiovascular conditions, children, and adults over 65, should review the daily breakdown below and follow local air-quality advisories on high-AQI days.
Sensitive group advisory
People with asthma, COPD, heart disease, children, pregnant women, and adults 65+ should follow EPA AQI alerts daily and limit outdoor exertion when AQI exceeds 100. Real-time conditions: airnow.gov.
The dominant pollutant is Ozone, driving AQI on 220 of 365 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Burleigh County. Highest Good-day share: 2020 (82.5%, 302 of 366 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 302 | 64 | 0 | 0 | 37 | 77 |
| 2021 | 265 | 83 | 12 | 5 | 38 | 183 |
| 2022 | 260 | 105 | 0 | 0 | 39 | 99 |
| 2023 | 225 | 118 | 14 | 7 | 42 | 272 |
| 2024 | 268 | 88 | 9 | 1 | 39 | 174 |
| 2025 | 285 | 68 | 8 | 3 | 39 | 218 |
How does Burleigh County compare?
How Burleigh County compares
Good-day share better than typical
Burleigh County 78.1%
Aiken County, South Carolina 90.6%
Typical US county 76.0%
Median AQI about typical
Burleigh County 39
Aiken County, South Carolina 39
Typical US county 39
Unhealthy days / yr worse than typical
Burleigh County 4
Aiken County, South Carolina 0
Typical US county 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Burleigh County (39), not geographic neighbors.
Aiken County, South Carolina
Median AQI 39 · 90.6% Good-day share
Albany County, New York
Median AQI 39 · 68.5% Good-day share
Anderson County, Tennessee
Median AQI 39 · 94.3% Good-day share
Bay County, Michigan
Median AQI 39 · 70.4% Good-day share
Berkeley County, West Virginia
Median AQI 39 · 83.6% Good-day share
Boyd County, Kentucky
Median AQI 39 · 80.0% 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).
Berkshire County, Massachusetts
78.1% Good-day share · median AQI 38
Westmoreland County, Pennsylvania
78.2% Good-day share · median AQI 39
Fairfax County, Virginia
77.8% Good-day share · median AQI 42
Greene County, Pennsylvania
77.8% Good-day share · median AQI 40
Tehama County, California
77.8% Good-day share · median AQI 38
Santa Fe County, New Mexico
78.4% Good-day share · median AQI 44
North Dakota counties on the map
Geographic containment only, other monitored counties in North Dakota, independent of AQI or pollutant match.
What Burleigh County's air means for you
On most days the air here is fine, but Ozone drives 4 unhealthy-or-worse days a year that sensitive groups should plan around.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-Ozone days, the guide explains what a median of 39 means for exposure. Health guidance
- See how Burleigh County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Burleigh County with its North Dakota neighbours before drawing a conclusion about the region. All of North Dakota
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 Burleigh County, North Dakota? ▼
Burleigh County has a median Air Quality Index (AQI) of 39, rated "Good." 78.1% of monitored days (285 out of 365) had good air quality in 2025.
What is the main pollutant in Burleigh County? ▼
The primary pollutant in Burleigh County is Ozone (O3), which was the main AQI driver on 220 days (60% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Burleigh County have? ▼
In 2025, Burleigh County recorded 4 unhealthy air days (3 Unhealthy, 1 Very Unhealthy, 0 Hazardous). The maximum AQI reached 218.
Is the air quality in Burleigh County getting better or worse? ▼
Air quality in Burleigh 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 82.5% (302 of 366 days). Lowest qualifying Good-day share: 2023 at 61.8% (225 of 365 days).
What does AQI 39 mean for health? ▼
Burleigh County's median AQI of 39 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Burleigh County compare to other counties in North Dakota? ▼
Burleigh County has 78.1% good air days. Nearby counties in North Dakota: Billings (82.7% good), Burke (76.2% good), Cass (76.2% good), Dunn (79.7% good), McKenzie (80.8% good), Mercer (80.3% good).
What is the 90th percentile AQI in Burleigh County? ▼
The 90th percentile AQI for Burleigh County is 60, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 218 (Very Unhealthy).
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 Burleigh County, North Dakota · 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.