Metro area air quality · 2024

Houston-The Woodlands-Sugar Land, TX

Median AQI 63 (Moderate). 11.8% of monitored days rated Good across this metro's EPA monitoring network.

63
Median AQI
11.8%
Good-air days
17
Unhealthy days
1%
Cleaner than US metros

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

Insights: Houston-The Woodlands-Sugar Land, TX metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 63 over 366 measured days in 2024, which corresponds to a Moderate band and a Very Poor metro-wide health grade. The monitored-day split lands at 43 Good days (12%), 260 Moderate (71%), and 46 Unhealthy-for-Sensitive-Groups (13%). The 90th-percentile AQI finished at 122 while the highest single-day reading hit 201 (Very Unhealthy). Metro residents averaged roughly 3.5 clean-air days per 30-day window across the reporting year.

Across the 2020–2024 trend window, good days shifted by -55 and the median AQI moved +6 points, which classifies the multi-year trajectory as worsening. The metro recorded 17 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 El Centro, CA (22.7% good, AQI 63); Denver-Aurora-Lakewood, CO (19.9% good, AQI 64); Las Cruces, NM (26.5% good, AQI 62).

Air Quality Summary

Median AQI

63

Moderate

Good Days

11.8%

43 of 366 days

Max AQI

201

Very Unhealthy

Health Grade

Very Poor

90th pct: 122

AQI Day Breakdown (2024)

Distribution of 366 monitored days across EPA AQI categories.

Good

43

12%

Moderate

260

71%

USG

46

13%

Unhealthy

16

4%

Very Unhealthy

1

0%

Hazardous

0

0%

Health Impact Assessment

Very Poor

The Houston-The Woodlands-Sugar Land, TX metro area's air quality is rated Very Poor based on 11.8% good air days. There were 17 unhealthy days in 2024 when outdoor activity should be limited.

Air quality reached unhealthy levels on 17 days in 2024 (16 Unhealthy, 1 Very Unhealthy). Sensitive groups, including people with asthma, COPD, cardiovascular conditions, children, and adults over 65, should review the daily breakdown and follow local advisories.

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.

How does the Houston-The Woodlands-Sugar Land, TX metro compare?

How Houston-The Woodlands-Sugar Land, TX compares

Good-day share worse than US avg
Houston-The Woodlands-Sugar Land, TX 11.8%
El Centro, CA 22.7%
US average 70.2%
Median AQI worse than US avg
Houston-The Woodlands-Sugar Land, TX 63
El Centro, CA 63
US average 41
Unhealthy days / yr worse than US avg
Houston-The Woodlands-Sugar Land, TX 17
El Centro, CA 8
US average 1

5-Year Air Quality Trend

Air quality is worsening in the Houston-The Woodlands-Sugar Land, TX metro. Best year: 2020 (98 good days).

Year Good Moderate Unhealthy Median AQI
2020 98 244 3 57
2021 60 275 9 59
2022 50 276 6 61
2023 36 272 11 65
2024 43 260 16 63

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to Houston-The Woodlands-Sugar Land, TX.

More Air Quality Data

Explore EPA air quality rankings and guides across U.S. metros and counties.

Air Quality Guides

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

Frequently Asked Questions

What is the air quality in the Houston-The Woodlands-Sugar Land, TX metro area?
The Houston-The Woodlands-Sugar Land, TX metro area has a median Air Quality Index (AQI) of 63, rated "Moderate." 11.8% of monitored days (43 out of 366) had good air quality in 2024.
How many unhealthy air days does Houston-The Woodlands-Sugar Land, TX have?
In 2024, the Houston-The Woodlands-Sugar Land, TX metro area recorded 17 unhealthy air days (16 Unhealthy, 1 Very Unhealthy, 0 Hazardous). The maximum AQI reached 201.
Is air quality in Houston-The Woodlands-Sugar Land, TX getting better or worse?
Air quality in the Houston-The Woodlands-Sugar Land, TX metro is worsening based on 5-year trends (2020-2024). Best year: 2020 with 98 good days. Worst year: 2023 with 36 good days.
What does AQI 63 mean for health?
An AQI of 63 is "Moderate", air quality is acceptable, but some pollutants may pose a moderate health concern for a small number of sensitive individuals.
What is the 90th percentile AQI for Houston-The Woodlands-Sugar Land, TX?
The 90th percentile AQI for the Houston-The Woodlands-Sugar Land, TX metro area is 122, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 201 (Very Unhealthy).
How does Houston-The Woodlands-Sugar Land, TX compare to other metro areas?
The Houston-The Woodlands-Sugar Land, TX metro has 11.8% good air days. Similar metros: El Centro, CA (22.7% good), Denver-Aurora-Lakewood, CO (19.9% good), Las Cruces, NM (26.5% 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.

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