San Antonio, TX Air Quality & Smog

Dominant pollutants, when smog is worst, notable historical episodes, and local agency resources for San Antonio, TX — plus how to check the current AQI. For real-time readings, the free Smog Report iOS app pulls live air quality from EPA AirNow.

Dominant pollutants

ozone (spring-summer), PM2.5 (Saharan dust + agricultural smoke).

Seasonal pattern: when smog is worst

San Antonio was designated nonattainment for the 2015 ozone standard in 2018. Long hot summers, I-10 corridor traffic, and proximity to Eagle Ford Shale activity contribute. Saharan dust events affect the metro each summer.

A recent or notable event

September 2025 — a multi-day Saharan dust transport event combined with prescribed-burn smoke pushed Bexar County AQI past 150 for several days.

Local agencies and resources

TCEQ runs the AirNow monitors. AACOG coordinates the regional ozone advance plan.

• Texas Commission on Environmental Quality (TCEQ)
• Alamo Area Council of Governments (AACOG)

How to check air quality in San Antonio

The EPA's AirNow.gov publishes the canonical reading from the nearest regulatory monitor. For glanceable iPhone access — including widgets, Live Activities, Siri voice queries, and Apple Watch — install Smog Report. It's free, requires no account, and pulls from the same AirNow API.

For San Antonio-specific advisories and alerts that go beyond the federal AirNow feed, check the agency pages above directly.

Common questions about San Antonio air quality

Why does San Antonio have air-quality and smog problems?

San Antonio was designated nonattainment for the 2015 ozone standard in 2018. Long hot summers, I-10 corridor traffic, and proximity to Eagle Ford Shale activity contribute. Saharan dust events affect the metro each summer.

What are the main air pollutants in San Antonio?

San Antonio's dominant pollutants are ozone (spring-summer), PM2.5 (Saharan dust + agricultural smoke). The AQI on any given day is usually driven by whichever of these is highest.

Has San Antonio had a major air-quality or smog event?

September 2025 — a multi-day Saharan dust transport event combined with prescribed-burn smoke pushed Bexar County AQI past 150 for several days.

How can I check San Antonio's air quality right now?

The EPA's AirNow.gov publishes the official reading from the nearest regulatory monitor. For live AQI on your iPhone — with home-screen widgets, Lock Screen Live Activities, Siri, and Apple Watch — the free Smog Report app pulls from the same AirNow feed. No account is required.

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