Air quality · North Dakota
Air quality in North Dakota
Across the 3 North Dakota ZIPs with EPA county air-quality data, the median day is Good in all 3 (median AQI 37–39). 18 days across those counties reached Unhealthy or worse in 2025. This is a 2025 county annual summary, not a live reading.
Last verified 2026-09-24 · methodology
Air quality by ZIP code in North Dakota
EPA's 2025 annual summary for each ZIP's county. Median AQI is the typical day; lower is cleaner.
| ZIP | Median AQI | Good days | Unhealthy or worse |
|---|---|---|---|
| 58102FargoCass County | 37 Good | 275 of 361 | 7 |
| 58503Bismarck (ND)Burleigh County | 39 Good | 285 of 365 | 4 |
| 58103Fargo (South)Cass County | 37 Good | 275 of 361 | 7 |
County-level figures from EPA Air Quality System (AQS), annual county summary, joined to each ZIP by county. None of them is a measurement at a specific address.
What lands here
Pages show the 2025 median AQI category (Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, Hazardous) for the ZIP's county, plus the year's max/90th-percentile AQI and day-count breakdown by category.
Source & refresh
EPA Air Quality System (AQS), annual county summary. Refreshed annual (epa aqs publication). Primary source →
North Dakota top concern
Radon Zone 1, flooding (Red River), wind
North Dakota is uniformly Zone 1 radon. Red River of the North FEMA AE zones affect Fargo, Grand Forks. Wind exposure is significant statewide.
See North Dakota state page for the full state-level rollup across all 12 dimensions.
Read more on air quality
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Plain-English guide to the EPA Air Quality Index (AQI) and the 6 categories from Good to Hazardous. When to take precautions and which pollutants matter.
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