North Dakota · County air quality · 2025

Burleigh County, North Dakota

Median AQI 41 (Good). 77.5% of monitored days rated Good, direct from EPA Air Quality System stations.

41
Median AQI
77.5%
Good-air days
4
Unhealthy days
45%
Cleaner than US counties

The verdict

According to EPA Air Quality System monitoring data, Burleigh County's air is good on balance, more polluted than the median US county, a median AQI of 41 with 77.5% of 244 monitored days in the Good band, driven mainly by Ozone.

41
median AQI · Good
77.5%
days rated Good
Ozone
main pollutant
45%
cleaner than US counties

4 days reached Unhealthy or worse; the worst single reading hit AQI 218.

Data updated July 2026

Burleigh County AQI category distribution Stacked-segment bar showing the share of monitored days that fell in each EPA AQI category, Good, Moderate, USG, Unhealthy, Very Unhealthy, Hazardous, with median AQI marker. AQI category distribution 244 monitored days G M Median AQI 41 0 50 100 150 200 300 500 Burleigh County
  • Good · 189 d · 77.5%
  • Moderate · 43 d · 17.6%
  • USG · 8 d · 3.3%
  • Unhealthy · 3 d · 1.2%
  • Very Unhealthy · 1 d · 0.4%

How did Burleigh County's air break down in 2025?

Across 244 monitored days, 189 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). 244 days monitored. Median AQI: 41 (Good).

Insights: Burleigh County, North Dakota. EPA monitors recorded a median Air Quality Index of 41 across 244 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 189 (77%) fell in the Good band (AQI 0–50), 43 (18%) registered Moderate readings, and 8 (3%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 67, while the worst single-day peak hit 218 (Very Unhealthy). Residents averaged about 23.2 clean-air days per 30-day window during the monitoring year.

The full pollutant mix ranks as Ozone (182 days), PM2.5 (60 days), NO2 (1 days), CO (1 days). Across the 2020–2025 trend window, good days shifted by -113 and the median AQI moved +4 points, placing the multi-year trajectory at worsening. Residents and visitors experienced 4 unhealthy-or-worse days combined, periods when the EPA recommends sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Billings (80.3% good, AQI 40); Burke (72.8% good, AQI 40); Cass (73.2% good, AQI 39); Dunn (78.6% good, AQI 40); McKenzie (79.0% good, AQI 41); Mercer (80.3% good, AQI 39).

Air Quality Summary

Median AQI

41

Good

Good Days

77.5%

189 of 244 monitored days

2.5pp vs 75% target

Max AQI Recorded

218

Very Unhealthy

Health Grade

Good

90th-pct AQI 67

Burleigh County, Good days share 77.5%
National avg

Share of monitored days at AQI 0-50 (Good band).

Burleigh County, Unhealthy-or-worse share 1.6%
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 244 monitored days across EPA AQI categories.

Good

189

77%

Moderate

43

18%

USG

8

3%

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.

Burleigh County, North Dakota criteria pollutant distribution Stratified-band visualization showing the share of monitored days each criteria pollutant (PM2.5, PM10, O3, NO2, CO) was the primary AQI driver. Ozone · 74.6% PM2.5 · 24.6% 0% 25% 50% 75% 100% Burleigh County, North Dakota · 244 monitored days Criteria pollutant column
  • Ozone · 182 days · 74.6%
  • PM2.5 · 60 days · 24.6%
  • NO₂ · 1 days · 0.4%
  • CO · 1 days · 0.4%
Ozone (O3) 182 days (75%)

How Ozone affects health →

Fine Particles (PM2.5) 60 days (25%)

How PM2.5 affects health →

Nitrogen Dioxide (NO2) 1 days (0%)

How NO2 affects health →

Carbon Monoxide (CO) 1 days (0%)

How CO affects health →

Health Impact Assessment

Good

Burleigh County's air quality is rated Good based on 77.5% 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 182 of 244 monitored days.

5-Year Air Quality Trend

Air quality is worsening in Burleigh County. Best year: 2020 (302 good days).

Year Good Moderate USG Unhealthy Median AQI
2020 302 64 0 0 37
2021 265 83 12 5 38
2022 260 105 0 0 39
2023 225 118 14 7 42
2024 268 88 9 1 39
2025 189 43 8 3 41

How does Burleigh County compare?

How Burleigh County compares

Good-day share better than US avg
Burleigh County 77.5%
Billings County, North Dakota 80.3%
US average 76.5%
Median AQI worse than US avg
Burleigh County 41
Billings County, North Dakota 40
US average 38
Unhealthy days / yr worse than US avg
Burleigh County 4
Billings County, North Dakota 4
US average 0

Other Counties in North Dakota

Air quality comparison for nearby counties in North Dakota.

Counties with Similar Air Quality

Counties across the US with a similar median AQI to Burleigh County.

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 41 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 244 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 Burleigh County, North Dakota?
Burleigh County has a median Air Quality Index (AQI) of 41, rated "Good." 77.5% of monitored days (189 out of 244) 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 182 days (75% 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 based on 5-year trends (2020-2025). Best year: 2020 with 302 good days. Worst year: 2025 with 189 good days.
What does AQI 41 mean for health?
Burleigh County's median AQI of 41 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 Burleigh County compare to other counties in North Dakota?
Burleigh County has 77.5% good air days. Nearby counties in North Dakota: Billings (80.3% good), Burke (72.8% good), Cass (73.2% good), Dunn (78.6% good), McKenzie (79.0% good), Mercer (80.3% good).
What is the 90th percentile AQI in Burleigh County?
The 90th percentile AQI for Burleigh County is 67, 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.

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.