Houston Air Quality in January

Across 2019–2025, Houston's January air quality had a median AQI of 55 (Moderate) over 217 monitored days in the Houston-The Woodlands-Sugar Land, TX area. 4.1% of January days (9 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 84.3% of days. The cleanest January on record here was 2022 (median AQI 58, 0 days above 100) and the worst was 2023 (median 60, 3 days above 100, peak AQI 122).

55
Median AQI
Moderate
4.1%
Days above AQI 100
9 of 217 days
74
90th percentile AQI
worst 1 day in 10
190
Peak AQI
Unhealthy
PM2.5
Main pollutant
84.3% of days
24.4%
Good days
53 of 217
  • Good: 24.4%
  • Moderate: 71.4%
  • Unhealthy for Sensitive Groups: 2.3%
  • Unhealthy or worse: 1.8%

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QUICK ANSWER

How is the air in Houston in January?

Moderate on a typical day: median AQI 55 across 2019–2025, with 4.1% of January days above AQI 100. Fine particulate matter (PM2.5) is the main driver.

  • 24.4% of January days were Good (AQI 0–50), 71.4% Moderate (51–100).
  • 9 days of 217 reached AQI 101+; the January peak was 190.
  • Best January: 2022; worst January: 2023.

Frequently asked questions

What is the air quality like in Houston in January?

Across 2019–2025, the median daily AQI in Houston in January was 55 (Moderate). 24.4% of days were Good, 71.4% Moderate, and 4.1% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.

Is January a good time for outdoor exercise in Houston?

A typical January day in Houston is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 24 of January days (4.1%) 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 January air quality problems?

Fine particulate matter (PM2.5) set the daily AQI on 84.3% of January days in Houston. The highest January AQI recorded in 2019–2025 was 190 (Unhealthy), in 2023.

Houston January air quality, year by year

Houston January air quality by year (Houston-The Woodlands-Sugar Land, TX, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
201931521176PM2.5
202031531190PM2.5
202131542130PM2.5
2022cleanest3158083PM2.5
2023worst31603122PM2.5
202431561184PM2.5
202531581168PM2.5

What January air means in Houston

A typical January day in Houston is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 24 of January days (4.1%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

January's median AQI of 55 is below Houston's whole-year median of 61, making it one of the area's cleaner periods. Nationally, the median January AQI across every EPA metro area (95,602 metro-days, 2019–2025) is 39, so Houston runs above the national January norm; 4.1% of its January days topped AQI 100 versus 0.7% nationally (above average).

January is part of Houston's winter season (December, January, February); the winter 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.