Metro area air quality · 2024

Bismarck, ND

Median AQI 40 (Good). 73.0% of monitored days rated Good across this metro's EPA monitoring network.

40
Median AQI
73.0%
Good-air days
2
Unhealthy days
49%
Cleaner than US metros

Aggregated from EPA Air Quality System (2024), 366 monitored days. EPA AQS → · NOAA →

Insights: Bismarck, ND metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 40 over 366 measured days in 2024, which corresponds to a Good band and a Moderate metro-wide health grade. The monitored-day split lands at 267 Good days (73%), 88 Moderate (24%), and 9 Unhealthy-for-Sensitive-Groups (2%). The 90th-percentile AQI finished at 65 while the highest single-day reading hit 174 (Unhealthy). Metro residents averaged roughly 21.9 clean-air days per 30-day window across the reporting year.

Across the 2020–2024 trend window, good days shifted by -28 and the median AQI moved +0 points, which classifies the multi-year trajectory as worsening. The metro recorded 2 unhealthy-or-worse days combined, on those days the EPA recommends that sensitive groups limit prolonged outdoor exertion, and many schools and athletic programs adjust outdoor activity accordingly. Metros with comparable AQI profiles include Cambridge, MD (80.3% good, AQI 40); Charleston, WV (77.8% good, AQI 40); Charlottesville, VA (78.9% good, AQI 40).

Air Quality Summary

Median AQI

40

Good

Good Days

73.0%

267 of 366 days

Max AQI

174

Unhealthy

Health Grade

Moderate

90th pct: 65

AQI Day Breakdown (2024)

Distribution of 366 monitored days across EPA AQI categories.

Good

267

73%

Moderate

88

24%

USG

9

2%

Unhealthy

2

1%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The Bismarck, ND metro area's air quality is rated Moderate based on 73.0% good air days. There were 2 unhealthy days in 2024 when outdoor activity should be limited.

Air quality is acceptable most days, but 9 days reached "Unhealthy for Sensitive Groups" and peak AQI reached 174. Sensitive groups should monitor real-time conditions at AirNow.gov.

How does the Bismarck, ND metro compare?

How Bismarck, ND compares

Good-day share better than US avg
Bismarck, ND 73.0%
Cambridge, MD 80.3%
US average 70.2%
Median AQI better than US avg
Bismarck, ND 40
Cambridge, MD 40
US average 41
Unhealthy days / yr worse than US avg
Bismarck, ND 2
Cambridge, MD 0
US average 1

5-Year Air Quality Trend

Air quality is worsening in the Bismarck, ND metro. Best year: 2020 (295 good days).

Year Good Moderate Unhealthy Median AQI
2020 295 71 0 40
2021 234 112 8 43
2022 246 119 0 43
2023 210 129 9 46
2024 267 88 2 40

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to Bismarck, ND.

Cambridge, MD

AQI 40 · 80.3% good

40

Charleston, WV

AQI 40 · 77.8% good

40

Charlottesville, VA

AQI 40 · 78.9% good

40

Daphne-Fairhope-Foley, AL

AQI 40 · 78.3% good

40

Hartford-West Hartford-East Hartford, CT

AQI 40 · 75.4% good

40

Jefferson City, MO

AQI 40 · 95.0% good

40

More Air Quality Data

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Worst Air Quality

Counties and metros with the most unhealthy air days.

All Metro Areas

Annual AQI by CBSA for every monitored U.S. metro area.

Best and Worst City Air

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Air Quality Guides

Learn more about air quality monitoring, pollutants, and health impacts.

Understanding AQI

What each AQI level means and who is most at risk.

Best & Worst City Air Quality

Metro area air quality rankings and what drives urban pollution.

Health Effects of Air Pollution

How PM2.5 and ozone exposure affects respiratory and cardiovascular health.

Frequently Asked Questions

What is the air quality in the Bismarck, ND metro area? ▼
The Bismarck, ND metro area has a median Air Quality Index (AQI) of 40, rated "Good." 73.0% of monitored days (267 out of 366) had good air quality in 2024.
How many unhealthy air days does Bismarck, ND have? ▼
In 2024, the Bismarck, ND metro area recorded 2 unhealthy air days (2 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 174.
Is air quality in Bismarck, ND getting better or worse? ▼
Air quality in the Bismarck, ND metro is worsening based on 5-year trends (2020-2024). Best year: 2020 with 295 good days. Worst year: 2023 with 210 good days.
What does AQI 40 mean for health? ▼
An AQI of 40 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.
What is the 90th percentile AQI for Bismarck, ND? ▼
The 90th percentile AQI for the Bismarck, ND metro area is 65, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 174 (Unhealthy).
How does Bismarck, ND compare to other metro areas? ▼
The Bismarck, ND metro has 73.0% good air days. Similar metros: Cambridge, MD (80.3% good), Charleston, WV (77.8% good), Charlottesville, VA (78.9% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2024. The AQS collects ambient air monitoring data from state, local, and tribal monitoring agencies across the United States.

Metrics: Air Quality Index (AQI) is calculated using EPA-standard breakpoints for six criteria pollutants: PM2.5, PM10, Ozone, NO2, CO, and SO2. Median AQI, max AQI, and 90th percentile AQI are computed from daily measurements. Good days percentage reflects days with AQI 0–50.

Coverage: 501 metro areas (Core Based Statistical Areas). Only metros with active monitoring stations are included. Unmonitored areas are not represented.

Read our methodology , how this data is sourced, computed, and verified.

Source: U.S. EPA, AirNow / AQS Air Quality Index readings and pollutant concentrations · 2025