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San Antonio, TX Air Quality Index (AQI) Today

TXDominant: PM2.5 LIVE

Readings collected automatically every hour; text written and checked by BreatheCheck Editorial. How this page is made →

Right now: San Antonio is at 52, moderate.

Is the air safe to breathe in San Antonio today?

52 Moderate “Unhealthy for everyone” starts at 151 — not 201.

In San Antonio, BreatheCheck reads 52 as Go. The cutoffs: go below 101, keep it short and easy from 101 to 150, move it indoors above 150. These are our own thresholds, drawn on the EPA bands — EPA itself classifies 101–150 as Unhealthy for Sensitive Groups and does not tell you how long to stay out.

Go AQI 0–100

Normal outdoor plans. No change needed.

Short & unloaded AQI 101–150

A 20-minute dog walk, not a 2.5-hour run. Keep it brief and easy.

Don’t go AQI 151+

Move it indoors. Above 200 that becomes everyone, not just sensitive groups.

Go Every combination lands the same way at this reading — a hard hour is no different from an easy twenty minutes. The two dials separate above 80.

All the thresholds people reported, and who reported them
  • 60 Asthmatic runnerone runner’s own 156-run log
  • 75–100 Daycare / schoolparents and staff in one r/toddlers thread, Aug 2025 — not a published rule
  • 100 Parentcommunity-reported, escalating at 150 and 200
  • 110 Runnercommunity-reported

EPA classifies 101–150 as Unhealthy for Sensitive Groups. That is an attributed classification, not a verdict on your lungs specifically.

If you’re staying in, filter the room you’re actually in

A portable HEPA unit or a Corsi-Rosenthal box — one builder put theirs at about $130 for a 12×14 bedroom. We don’t default to a MERV-13 swap in whole-house HVAC: it can restrict airflow, and the safe version needs a static-pressure check first.

See options

PM2.5

2.3 low · modelled

UV hour by hour in San Antonio →

1 of 30 days we have recorded

The record, day by day →

Highest ozone north of the urban core

TCEQ runs three regulatory ozone monitors in the San Antonio area: San Antonio Northwest, Calaveras Lake, and Camp Bullis. The one that most often records the region’s highest values, Camp Bullis, sits on the northern edge of the built-up area rather than inside it.

AACOG’s conceptual model for the region accounts for that. It describes the highest concentrations forming north and northwest of the urban core, which is what a persistent southeasterly Gulf wind produces: precursors leave the city, keep reacting as they travel, and reach their peak over the rising ground of the Balcones Escarpment. On a hot, light-wind summer afternoon the air over the northwest suburbs and the Hill Country parks beyond them can be worse than the air over the River Walk, which inverts what most people assume about city air.

The regulatory line is drawn on county borders instead. When EPA finished its 2015 ozone designations in July 2018 it named Bexar County alone, classified marginal, and designated the seven surrounding counties — Atascosa, Bandera, Comal, Guadalupe, Kendall, Medina and Wilson — attainment or unclassifiable. That took effect on September 24, 2018. Comal, Kendall and Bandera lie in the same northward direction the plume travels, on the far side of a line that the air itself does not observe.

Where this number sits

Of the 121 US metros reporting to us right now, San Antonio is number 26 and number 2 of the 5 we track in Texas. The pollutant driving it today is PM2.5.

Nearby metros we also measure, and what they read at the same hour:

Why a metro a short drive away reads differently →

AirNow’s San Antonio reporting area, about 0.4 miles from the metro centre.

What has air quality in San Antonio actually been?

Daily maximum, our own readings. 30 days since 2026-08-16; nothing back-filled. Why we keep our own →

1 of the 30 days we have recorded so far went above AQI 100.

Daily maximum AQI recorded for San Antonio, TX
DateDaily max AQIEPA bandHours read
69Moderate22
52Moderate23
57Moderate23
57Moderate23
38Good23
40Good22
48Good23
45Good23
46Good23
53Moderate23
53Moderate23
60Moderate24
54Moderate23
64Moderate23
64Moderate23
46Good23
67Moderate23
101Unhealthy for Sensitive Groups22
60Moderate23
63Moderate23
66Moderate23
58Moderate24
58Moderate23
83Moderate23
93Moderate23
75Moderate23
66Moderate23
72Moderate23
66Moderate26
53Moderate6 — partial day

Questions about San Antonio

What is the air quality in San Antonio right now?

AQI 52 — Moderate. That is number 26 of the 121 US metros reporting to us at this hour.

Which monitor does this number come from?

San Antonio, about 0.4 miles from the metro centre. One instrument reports for the whole metro, so the side farthest from it is the least well described.

How does San Antonio compare with metros nearby?

At this hour: Austin 52, Houston 49, Fort Worth 42, Dallas 42. Readings that close together suggest one airshed rather than local sources.

Does this include pollen?

No. The AQI covers PM2.5, PM10, ozone, NO₂, SO₂ and CO. A high-pollen day can read clean here and still put someone in bed.

What the number means, band by band → · UV in San Antonio → · Why apps disagree →

Updated