Houston Air Quality in October
Across 2019–2025, Houston's October air quality had a median AQI of 62 (Moderate) over 217 monitored days in the Houston-The Woodlands-Sugar Land, TX area. 18.0% of October days (39 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 46.1% of days. The cleanest October on record here was 2023 (median AQI 57, 1 day above 100) and the worst was 2024 (median 82, 11 days above 100, peak AQI 192).
- Good: 17.1%
- Moderate: 65.0%
- Unhealthy for Sensitive Groups: 15.7%
- Unhealthy or worse: 2.3%
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How is the air in Houston in October?
Moderate on a typical day: median AQI 62 across 2019–2025, with 18.0% of October days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓17.1% of October days were Good (AQI 0–50), 65.0% Moderate (51–100).
- ✓39 days of 217 reached AQI 101+; the October peak was 192.
- ✓Best October: 2023; worst October: 2024.
Frequently asked questions
What is the air quality like in Houston in October?▾
Across 2019–2025, the median daily AQI in Houston in October was 62 (Moderate). 17.1% of days were Good, 65.0% Moderate, and 18.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is October a good time for outdoor exercise in Houston?▾
A typical October day in Houston is Moderate (median AQI 62): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 6 of October days (18.0%) 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 October air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 46.1% of October days in Houston. The highest October AQI recorded in 2019–2025 was 192 (Unhealthy), in 2024.
Houston October air quality, year by year
Houston October 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 | 53 | 2 | 140 | PM2.5 |
| 2020 | 31 | 57 | 5 | 140 | PM2.5 |
| 2021 | 31 | 66 | 4 | 166 | PM2.5 |
| 2022 | 31 | 79 | 9 | 154 | O3 |
| 2023cleanest | 31 | 57 | 1 | 101 | PM2.5 |
| 2024worst | 31 | 82 | 11 | 192 | O3 |
| 2025 | 31 | 64 | 7 | 151 | O3 |
What October air means in Houston
A typical October day in Houston is Moderate (median AQI 62): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 6 of October days (18.0%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
October's median AQI of 62 is in line with Houston's whole-year median of 61, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so Houston runs above the national October norm; 18.0% of its October days topped AQI 100 versus 1.3% nationally (above average).
October is part of Houston's fall season (September, October, November); the fall 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 47 (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.