Houston Air Quality in August
Across 2019–2025, Houston's August air quality had a median AQI of 65 (Moderate) over 217 monitored days in the Houston-The Woodlands-Sugar Land, TX area. 25.4% of August days (55 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 52.1% of days. The cleanest August on record here was 2021 (median AQI 63, 1 day above 100) and the worst was 2024 (median 108, 16 days above 100, peak AQI 200).
- Good: 8.8%
- Moderate: 65.9%
- Unhealthy for Sensitive Groups: 20.3%
- Unhealthy or worse: 5.1%
Extra Protection for Houston Homes
Air quality in Houston is moderate (AQI 57), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
Recommended: Coway AP-1512HH Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
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How is the air in Houston in August?
Moderate on a typical day: median AQI 65 across 2019–2025, with 25.4% of August days above AQI 100. Ground-level ozone is the main driver.
- ✓8.8% of August days were Good (AQI 0–50), 65.9% Moderate (51–100).
- ✓55 days of 217 reached AQI 101+; the August peak was 202.
- ✓Best August: 2021; worst August: 2024.
Frequently asked questions
What is the air quality like in Houston in August?▾
Across 2019–2025, the median daily AQI in Houston in August was 65 (Moderate). 8.8% of days were Good, 65.9% Moderate, and 25.4% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is August a good time for outdoor exercise in Houston?▾
A typical August day in Houston is Moderate (median AQI 65): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 4 of August days (25.4%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Houston's August air quality problems?▾
Ground-level ozone set the daily AQI on 52.1% of August days in Houston. The highest August AQI recorded in 2019–2025 was 202 (Very Unhealthy), in 2024.
Houston August air quality, year by year
Houston August air quality by year (Houston-The Woodlands-Sugar Land, TX, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 58 | 3 | 202 | PM2.5 |
| 2020 | 31 | 63 | 9 | 182 | O3 |
| 2021cleanest | 31 | 63 | 1 | 126 | PM2.5 |
| 2022 | 31 | 53 | 2 | 108 | PM2.5 |
| 2023 | 31 | 97 | 15 | 187 | O3 |
| 2024worst | 31 | 108 | 16 | 200 | O3 |
| 2025 | 31 | 80 | 9 | 161 | O3 |
What August air means in Houston
A typical August day in Houston is Moderate (median AQI 65): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 4 of August days (25.4%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
August's median AQI of 65 is above Houston's whole-year median of 61, making it one of the area's dirtier periods. Nationally, the median August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so Houston runs above the national August norm; 25.4% of its August days topped AQI 100 versus 3.5% nationally (above average).
August is part of Houston's summer season (June, July, August); the summer page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Houston
The latest EPA AirNow observation puts Houston's AQI at 57 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Houston air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Houston-The Woodlands-Sugar Land, TX), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.