Houston Air Quality in Summer
Across 2019–2025, Houston's summer (June–August) air quality had a median AQI of 65 (Moderate) over 644 monitored days in the Houston-The Woodlands-Sugar Land, TX area. 17.8% of summer days (115 of 644) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 59.6% of days. The cleanest summer on record here was 2021 (median AQI 62, 9 days above 100) and the worst was 2024 (median 77, 30 days above 100, peak AQI 201).
- Good: 9.3%
- Moderate: 72.8%
- Unhealthy for Sensitive Groups: 13.5%
- Unhealthy or worse: 4.3%
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 summer?
Moderate on a typical day: median AQI 65 across 2019–2025, with 17.8% of summer days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓9.3% of summer days were Good (AQI 0–50), 72.8% Moderate (51–100).
- ✓115 days of 644 reached AQI 101+; the summer peak was 202.
- ✓Cleanest month: July; worst month: August.
Frequently asked questions
What is the air quality like in Houston in summer?▾
Across 2019–2025, the median daily AQI in Houston in summer was 65 (Moderate). 9.3% of days were Good, 72.8% Moderate, and 17.8% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is summer a good time for outdoor exercise in Houston?▾
A typical summer 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 6 of summer days (17.8%) 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 summer air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 59.6% of summer days in Houston. The highest summer AQI recorded in 2019–2025 was 202 (Very Unhealthy), in 2024.
Houston summer air quality, year by year
Houston summer 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 | 92 | 61 | 14 | 202 | PM2.5 |
| 2020 | 92 | 64 | 13 | 182 | PM2.5 |
| 2021cleanest | 92 | 62 | 9 | 179 | PM2.5 |
| 2022 | 92 | 59 | 10 | 179 | PM2.5 |
| 2023 | 92 | 74 | 25 | 197 | PM2.5 |
| 2024worst | 92 | 77 | 30 | 201 | O3 |
| 2025 | 92 | 67 | 14 | 172 | PM2.5 |
What summer air means in Houston
A typical summer 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 6 of summer days (17.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Summer'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 Summer AQI across every EPA metro area (308,645 metro-days, 2019–2025) is 46, so Houston runs above the national Summer norm; 17.8% of its Summer days topped AQI 100 versus 3.6% nationally (above average).
Within the season, July is the cleanest month (median AQI 62, 7.4% of days above 100) and August the worst (median 65, 25.4% above 100).
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 season 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.