Median AQI
53
Moderate
Texas · County air quality · 2025
Dallas County, Texas
Median AQI 53 (Moderate). 41.0% of monitored days rated Good, direct from EPA Air Quality System stations.
- 53
- Median AQI
- 41.0%
- Good-air days
- 1
- Unhealthy days
- 4%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Dallas County's air is moderate on balance, among the most polluted counties nationally, a median AQI of 53 with 41.0% of 212 monitored days in the Good band, driven mainly by PM2.5.
- 53
- median AQI · Moderate
- 41.0%
- days rated Good
- PM2.5
- main pollutant
- 4%
- cleaner than US counties
1 day reached Unhealthy or worse; the worst single reading hit AQI 304.
Data updated July 2026
- Good · 87 d · 41.0%
- Moderate · 120 d · 56.6%
- USG · 4 d · 1.9%
- Hazardous · 1 d · 0.5%
How did Dallas County's air break down in 2025?
Across 212 monitored days, 87 fell in the Good band (AQI 0–50) and 1 reached Unhealthy or worse. The worst single day peaked at AQI 304 (Hazardous).
EPA AQS →Air quality data from EPA Air Quality System (2025). 212 days monitored. Median AQI: 53 (Moderate).
Insights: Dallas County, Texas. EPA monitors recorded a median Air Quality Index of 53 across 212 measured days in 2025, earning a Moderate classification and a Poor health grade. Of those days, 87 (41%) fell in the Good band (AQI 0–50), 120 (57%) registered Moderate readings, and 4 (2%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 70, while the worst single-day peak hit 304 (Hazardous). Residents averaged about 12.3 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (132 days), Ozone (75 days), NO2 (4 days), PM10 (1 days). Across the 2020–2025 trend window, good days shifted by -131 and the median AQI moved +7 points, placing the multi-year trajectory at worsening. Residents and visitors experienced 1 unhealthy-or-worse days combined, periods when the EPA recommends sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Atascosa (58.0% good, AQI 45); Bell (61.3% good, AQI 47); Bexar (39.8% good, AQI 53); Bowie (57.3% good, AQI 47); Brazoria (84.8% good, AQI 33); Brazos (63.4% good, AQI 43).
Air Quality Summary
Good Days
41.0%
87 of 212 monitored days
-34.0pp vs 75% target
Max AQI Recorded
304
Hazardous
Health Grade
Poor
90th-pct AQI 70
Dallas County, Good days share 41.0%
National avg
Share of monitored days at AQI 0-50 (Good band).
Dallas County, Unhealthy-or-worse share 0.5%
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 212 monitored days across EPA AQI categories.
Good
87
41%
Moderate
120
57%
USG
4
2%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
1
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Dallas County.
- PM2.5 · 132 days · 62.3%
- Ozone · 75 days · 35.4%
- NO₂ · 4 days · 1.9%
- PM10 · 1 days · 0.5%
Health Impact Assessment
Poor
Dallas County's air quality is rated Poor based on 41.0% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.
Air quality posed significant health risk in 2025. Sensitive groups, including people with asthma, COPD, cardiovascular conditions, children, pregnant women, and adults over 65, should monitor AirNow.gov alerts and limit outdoor activity on Unhealthy (AQI 151+) and Very Unhealthy (201+) days. Peak readings reached AQI 304, well into the Hazardous range.
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 PM2.5, driving AQI on 132 of 212 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Dallas County. Best year: 2020 (218 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 218 | 142 | 6 | 0 | 46 | 135 |
| 2021 | 210 | 145 | 9 | 1 | 47 | 174 |
| 2022 | 164 | 184 | 17 | 0 | 52 | 148 |
| 2023 | 122 | 216 | 26 | 1 | 55 | 172 |
| 2024 | 129 | 218 | 16 | 3 | 55 | 185 |
| 2025 | 87 | 120 | 4 | 0 | 53 | 304 |
How does Dallas County compare?
How Dallas County compares
Good-day share worse than US avg
Dallas County 41.0%
Atascosa County, Texas 58.0%
US average 76.5%
Median AQI worse than US avg
Dallas County 53
Atascosa County, Texas 45
US average 38
Unhealthy days / yr worse than US avg
Dallas County 1
Atascosa County, Texas 0
US average 0
Other Counties in Texas
Air quality comparison for nearby counties in Texas.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Dallas County.
Bexar County, Texas
AQI 53 · 39.8% good
Cook County, Illinois
AQI 53 · 40.5% good
Cuyahoga County, Ohio
AQI 53 · 43.6% good
Jefferson County, Alabama
AQI 53 · 36.8% good
Kings County, California
AQI 53 · 39.8% good
Lake County, Indiana
AQI 53 · 38.8% good
What Dallas County's air means for you
On most days the air here is fine, but PM2.5 drives 1 unhealthy-or-worse day a year that sensitive groups should plan around.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 53 means for exposure. Health guidance
- See how Dallas County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Dallas County with its Texas neighbours before drawing a conclusion about the region. All of Texas
Based on 212 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 Dallas County, Texas? ▼
Dallas County has a median Air Quality Index (AQI) of 53, rated "Moderate." 41.0% of monitored days (87 out of 212) had good air quality in 2025.
What is the main pollutant in Dallas County? ▼
The primary pollutant in Dallas County is Fine Particles (PM2.5), which was the main AQI driver on 132 days (62% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Dallas County have? ▼
In 2025, Dallas County recorded 1 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 1 Hazardous). The maximum AQI reached 304.
Is the air quality in Dallas County getting better or worse? ▼
Air quality in Dallas County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 218 good days. Worst year: 2025 with 87 good days.
What does AQI 53 mean for health? ▼
Dallas County's median AQI of 53 falls in the "Moderate" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Dallas County compare to other counties in Texas? ▼
Dallas County has 41.0% good air days. Nearby counties in Texas: Atascosa (58.0% good), Bell (61.3% good), Bexar (39.8% good), Bowie (57.3% good), Brazoria (84.8% good), Brazos (63.4% good).
What is the 90th percentile AQI in Dallas County? ▼
The 90th percentile AQI for Dallas County is 70, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 304 (Hazardous).
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.