Houston, Texas Air Quality
Houston air quality today — the AQI, the main pollutant, and whether it’s safe to exercise outside right now
Houston, TX · Air quality right now
The air quality index in Houston, TX is 66 (Moderate) right now — acceptable for most people.
Is it safe to be outside in Houston today?
AQI 66 Yes — air quality is Moderate
Fine for most; unusually sensitive people can take it easy.Main pollutant: PM2.5Observed 8:00 AM CDT
Pollutants right now
- PM2.522 µg/m³Main pollutantfine particles — smoke, exhaust, soot
- PM1024 µg/m³coarse particles — dust, pollen, ash
- Ozone30 µg/m³smog — builds on hot, sunny days
- NO₂30 µg/m³nitrogen dioxide — traffic, combustion
ExerciseOK to run for most; sensitive athletes can ease the intensity.
How to read Houston’s air quality
Guides: The AQI Scale, Explained · Air Quality Alerts, Decoded · How to Read a Wildfire Smoke Map · Why Wildfire Smoke Travels 1,000 Miles.
Air quality over time in Houston
Across the EPA’s county records from 2020 to 2025, Houston’s cleanest year was 2020 (median AQI 56) and its most polluted was 2023 (median AQI 64); the typical (median) day has trended more polluted since 2020.
| Year | Median AQI | Unhealthy+ | Main pollutant | USG | Moderate | Good |
|---|---|---|---|---|---|---|
| 2020 | 56 | 2 | PM2.5 | 15 | 240 | 109 |
| 2021 | 58 | 7 | PM2.5 | 18 | 276 | 64 |
| 2022 | 60 | 5 | PM2.5 | 22 | 281 | 57 |
| 2023 | 64 | 10 | PM2.5 | 38 | 273 | 44 |
| 2024 | 61 | 14 | PM2.5 | 33 | 269 | 50 |
| 2025 | 62 | 10 | PM2.5 | 28 | 287 | 40 |
“USG” is Unhealthy for Sensitive Groups (AQI 101–150); “Unhealthy+” combines the Unhealthy, Very Unhealthy, and Hazardous days. In 2024 the EPA tightened the annual fine-particle (PM2.5) standard to 9 µg/m³ from the previous 12 µg/m³, so counties near the old limit read worse against the new one. Source: EPA AQS annual summaries, 2020–2025.
Frequently asked
- What was the worst year for air quality in Houston?
- In the EPA's 2020–2025 county records, 2023 had the most days above AQI 100: 48 days (38 Unhealthy for Sensitive Groups, 10 Unhealthy or worse). It also had the highest median AQI, 64.
- How many unhealthy air days does Houston have?
- Across 2020–2025, 9% of the days reported for Houston's county had an AQI above 100 (202 of 2192), about 34 days a year. 2025 had 38 days.
- What's the main air pollutant in Houston?
- PM2.5: it drove Houston's county AQI on the most days in every year of the EPA's 2020–2025 records.