# San Antonio, TX Air Quality Index (AQI) Today > Source: https://breathecheck.com/air-quality/us/texas/san-antonio/ > Live AQI for San Antonio, TX with a plain verdict — go, short and unloaded, or don't go — plus the monitor behind it and our own hourly record. # San Antonio, TX Air Quality Index (AQI) Today 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? 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. Above 200 this stops being a personal call: everyone indoors. Duration and intensity are two separate dials | Under 20 min | 20–60 min | Over an hour | | Easy | Go | Go | Go | | Moderate | Go | Go | Go | | Hard | Go | Go | Go | 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 . Where people actually draw the line **All the thresholds people reported, and who reported them** - 60 Asthmatic runner one runner’s own 156-run log - 75–100 Daycare / school parents and staff in one r/toddlers thread, Aug 2025 — not a published rule - 100 Parent community-reported, escalating at 150 and 200 - 110 Runner community-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. Dominant pollutant PM2.5 UV index 2.3 low · modelled UV hour by hour in San Antonio → Days above AQI 100 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: - Austin, TX — 74 miles away, AQI 52 - Houston, TX — 189 miles away, AQI 49 - Fort Worth, TX — 239 miles away, AQI 42 - Dallas, TX — 253 miles away, AQI 42 Why a metro a short drive away reads differently → Where this reading comes from 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. | Date | Daily max AQI | EPA band | Hours read | | 2026-09-14 | 69 | Moderate | 22 | | 2026-09-13 | 52 | Moderate | 23 | | 2026-09-12 | 57 | Moderate | 23 | | 2026-09-11 | 57 | Moderate | 23 | | 2026-09-10 | 38 | Good | 23 | | 2026-09-09 | 40 | Good | 22 | | 2026-09-08 | 48 | Good | 23 | | 2026-09-07 | 45 | Good | 23 | | 2026-09-06 | 46 | Good | 23 | | 2026-09-05 | 53 | Moderate | 23 | | 2026-09-04 | 53 | Moderate | 23 | | 2026-09-03 | 60 | Moderate | 24 | | 2026-09-02 | 54 | Moderate | 23 | | 2026-09-01 | 64 | Moderate | 23 | | 2026-08-31 | 64 | Moderate | 23 | | 2026-08-30 | 46 | Good | 23 | | 2026-08-29 | 67 | Moderate | 23 | | 2026-08-28 | 101 | Unhealthy for Sensitive Groups | 22 | | 2026-08-27 | 60 | Moderate | 23 | | 2026-08-26 | 63 | Moderate | 23 | | 2026-08-25 | 66 | Moderate | 23 | | 2026-08-24 | 58 | Moderate | 24 | | 2026-08-23 | 58 | Moderate | 23 | | 2026-08-22 | 83 | Moderate | 23 | | 2026-08-21 | 93 | Moderate | 23 | | 2026-08-20 | 75 | Moderate | 23 | | 2026-08-19 | 66 | Moderate | 23 | | 2026-08-18 | 72 | Moderate | 23 | | 2026-08-17 | 66 | Moderate | 26 | | 2026-08-16 | 53 | Moderate | 6 — 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 → ## Put this number in context On this page Alert me when San Antonio turns One email when it crosses your threshold. Updated 14 Sep 2026, 22:12 UTC