San Antonio Air Quality in January
Across 2019–2025, San Antonio's January air quality had a median AQI of 49 (Good) over 217 monitored days in the San Antonio-New Braunfels, TX area. 1.9% of January days (4 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 81.1% of days. The cleanest January on record here was 2025 (median AQI 44, 0 days above 100) and the worst was 2024 (median 49, 1 day above 100, peak AQI 199).
- Good: 52.5%
- Moderate: 45.6%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 1.4%
Extra Protection for San Antonio Homes
Air quality in San Antonio is moderate (AQI 52), 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.
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How is the air in San Antonio in January?
Good on a typical day: median AQI 49 across 2019–2025, with 1.9% of January days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓52.5% of January days were Good (AQI 0–50), 45.6% Moderate (51–100).
- ✓4 days of 217 reached AQI 101+; the January peak was 309.
- ✓Best January: 2025; worst January: 2024.
Frequently asked questions
What is the air quality like in San Antonio in January?▾
Across 2019–2025, the median daily AQI in San Antonio in January was 49 (Good). 52.5% of days were Good, 45.6% Moderate, and 1.9% 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 San Antonio?▾
A typical January day in San Antonio sits in the Good range (median AQI 49), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 53 of January days (1.9%) reached AQI 101+ in 2019–2025.
Which pollutant causes San Antonio's January air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 81.1% of January days in San Antonio. The highest January AQI recorded in 2019–2025 was 309 (Hazardous), in 2024.
San Antonio January air quality, year by year
San Antonio January air quality by year (San Antonio-New Braunfels, TX, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 48 | 1 | 175 | PM2.5 |
| 2020 | 31 | 46 | 1 | 106 | PM2.5 |
| 2021 | 31 | 55 | 0 | 71 | PM2.5 |
| 2022 | 31 | 52 | 0 | 93 | PM2.5 |
| 2023 | 31 | 39 | 1 | 309 | PM2.5 |
| 2024worst | 31 | 49 | 1 | 199 | PM2.5 |
| 2025cleanest | 31 | 44 | 0 | 64 | PM2.5 |
What January air means in San Antonio
A typical January day in San Antonio sits in the Good range (median AQI 49), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 53 of January days (1.9%) reached AQI 101+ in 2019–2025.
January's median AQI of 49 is below San Antonio's whole-year median of 55, 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 San Antonio runs above the national January norm; 1.9% of its January days topped AQI 100 versus 0.7% nationally (above average).
January is part of San Antonio's winter season (December, January, February); the winter page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in San Antonio
The latest EPA AirNow observation puts San Antonio's AQI at 52 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current San Antonio air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (San Antonio-New Braunfels, 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.