North Dakota · County air quality · 2025

Ward County, North Dakota

Median AQI 36 (Good). 79.4% of monitored days rated Good, direct from EPA Air Quality System stations.

36
Median AQI
79.4%
Good-air days
5
Unhealthy days
55%
Cleaner than US counties

Ward County's 2025 annual median AQI is 36 (Good), with 79.4% Good days

According to the U.S. EPA Air Quality System, Ward County, North Dakota posted a 2025 median AQI of 36 (Good) across 364 monitored days, with 79.4% rated Good and 5 unhealthy or worse. This is an annual comparison, not today's advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US
Ward County's 79.4% Good-day share places it cleaner than 55% of US counties in 2025.
Closest median-AQI peer
Ashland County (81.6% Good, median AQI 36) is the closest nationwide median-AQI peer to Ward County.
2020–2025 trend
Ward County's floor-qualifying Good-day share is worsening from 2020 to 2025 (94.0% → 79.6%).
Median AQI
Median AQI: 36

According to the 2025 EPA AQS county release on PlainAirData, Ward County, North Dakota ranks #233 of 951 by median AQI (36) and #431 by good-day share (79.4%). Ponce County, Puerto Rico is #1 of 951 by median AQI (3, 91.4% Good days) at good-day-share #159 ≠ largest of 7 at 100.0% Good days #1 by good-day share (100.0%, median AQI 9) at median-AQI #7.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Ward County's peak single-day AQI rose from 152 to 283 between the 2024 and 2025 EPA annual releases, a change of +131 points.
  • Ward County's Good-day share fell from 81.4% to 79.4% between the 2024 and 2025 EPA annual releases, a change of -2.0 percentage points.
  • Ward County's Unhealthy-category days rose from 2 to 4 between the 2024 and 2025 EPA annual releases, a change of +2 days.

Compared against 366 monitored days in 2024 and 364 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Data updated August 2026

Ward 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 364 monitored days G M Median AQI 36 0 50 100 150 200 300 500 Ward County
  • Good · 289 d · 79.4%
  • Moderate · 63 d · 17.3%
  • USG · 7 d · 1.9%
  • Unhealthy · 4 d · 1.1%
  • Very Unhealthy · 1 d · 0.3%

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

Across 364 monitored days, 289 fell in the Good band (AQI 0–50) and 5 reached Unhealthy or worse. The worst single day peaked at AQI 283 (Very Unhealthy).

EPA AQS →
Ward County, Good days share 79.4%
National avg

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

Ward County, Unhealthy-or-worse share 13.7%
National avg

Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).

Where Ward County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Ward County's Good-day share is 79.4% - cleaner than 55% of that comparison set.

Ward County Good-day share vs. every US county

Share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release

79.4% Cleaner than 55% higher than 55% of 951 US counties

0.0%–5.0%: 0 US counties (0%). Below this entry. 5.0%–10.0%: 1 US counties (0%). Below this entry. 10.0%–15.0%: 4 US counties (0%). Below this entry. 15.0%–20.0%: 4 US counties (0%). Below this entry. 20.0%–25.0%: 1 US counties (0%). Below this entry. 25.0%–30.0%: 5 US counties (1%). Below this entry. 30.0%–35.0%: 9 US counties (1%). Below this entry. 35.0%–40.0%: 4 US counties (0%). Below this entry. 40.0%–45.0%: 16 US counties (2%). Below this entry. 45.0%–50.0%: 16 US counties (2%). Below this entry. 50.0%–55.0%: 32 US counties (3%). Below this entry. 55.0%–60.0%: 50 US counties (5%). Below this entry. 60.0%–65.0%: 77 US counties (8%). Below this entry. 65.0%–70.0%: 93 US counties (10%). Below this entry. 70.0%–75.0%: 109 US counties (11%). Below this entry. 75.0%–80.0%: 114 US counties (12%). This entry sits in this band. 80.0%–85.0%: 123 US counties (13%). Above this entry. 85.0%–90.0%: 99 US counties (10%). Above this entry. 90.0%–95.0%: 117 US counties (12%). Above this entry. 95.0%–100.0%: 70 US counties (7%). Above this entry. 100.0%–105.0%: 7 US counties (1%). Above this entry. This county 0.0% 100% every floor-qualified US county, bucketed by value

Each bar is a band; taller bars hold more US counties. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source U.S. Environmental Protection Agency, Air Quality System (AQS) · 2025

Pollutant Breakdown

Days where each pollutant was the primary driver of AQI readings in Ward County.

Ward 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 · 55.5% PM2.5 · 44.5% 0% 25% 50% 75% 100% Ward County, North Dakota · 364 monitored days Criteria pollutant column
  • Ozone · 202 days · 55.5%
  • PM2.5 · 162 days · 44.5%

2024 daily-monitor rhythm in Ward County

Month-by-month median AQI from EPA day-level county monitors (366 reported days in 2024). Jul posted the highest typical readings (median AQI 63, peak 137); Dec was cleanest at median 28. Summer months (Jun–Aug) averaged median AQI 52 vs 30 in Dec–Feb. 2 days crossed Unhealthy (AQI >150) at least once that year.

0 10 20 30 40 50 60 70 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 30 32 36 41 42 40 63 52 41 35 31 28
Ward County median daily AQI by calendar month (2024, EPA daily county file)

Five-year seasonal record

EPA day-level county files · 2020–2024

1,816 daily readings show a recurring local pattern: Jul has the highest matched-month median AQI (51), while Dec is lowest (29). Each cell is that month’s median daily AQI, not a current-air forecast.

JanFebMarAprMayJunJulAugSepOctNovDec
2020 323435393941343637323430
2021 303337403844655735272531
2022 343638384043404539383131
2023 333544425173525562283026
2024 303236414240635241353128

Lower AQI is better. The colors summarize EPA AQI bands; gaps mean the county had no day-level record for that month.

Health Impact Assessment

Good

Ward County's air quality is rated Good based on 79.4% good air days. There were 5 unhealthy days in 2025 when outdoor activity should be limited.

Air quality reached unhealthy levels on 5 days in 2025 (4 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 202 of 364 monitored days.

5-Year Air Quality Trend

Air quality is worsening in Ward County. Highest Good-day share: 2020 (94.0%, 344 of 366 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2020 344 22 0 0 35
2021 284 62 10 4 37
2022 315 44 0 0 37
2023 244 101 13 6 42
2024 298 59 7 2 37
2025 289 63 7 4 36

How does Ward County compare?

How Ward County compares

Good-day share better than typical
Ward County 79.4%
Ashland County, Wisconsin 81.6%
Typical US county 76.0%
Median AQI better than typical
Ward County 36
Ashland County, Wisconsin 36
Typical US county 39
Unhealthy days / yr worse than typical
Ward County 5
Ashland County, Wisconsin 8
Typical US county 1

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 Ward County, North Dakota · 2020–2025

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Download this county's annual AQI row as CSV , with the same EPA fields and denominator shown on this page.

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.