Baltimore, MD Air Quality & Smog

Dominant pollutants, when smog is worst, notable historical episodes, and local agency resources for Baltimore, MD — 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 (summer), PM2.5 (port + industrial).

Seasonal pattern: when smog is worst

Baltimore's air quality is shaped by its port (one of the largest on the East Coast), the I-95 corridor, and the Sparrows Point industrial legacy. Summer ozone is the dominant problem; winter PM2.5 from heating + transport elevates.

A recent or notable event

June 2023 Canadian wildfire smoke briefly pushed Baltimore AQI above 200.

Local agencies and resources

MDE runs the AirNow monitors statewide.

• Maryland Department of the Environment (MDE)
• Baltimore City Health Department

How to check air quality in Baltimore

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

Common questions about Baltimore air quality

Why does Baltimore have air-quality and smog problems?

Baltimore's air quality is shaped by its port (one of the largest on the East Coast), the I-95 corridor, and the Sparrows Point industrial legacy. Summer ozone is the dominant problem; winter PM2.5 from heating + transport elevates.

What are the main air pollutants in Baltimore?

Baltimore's dominant pollutants are ozone (summer), PM2.5 (port + industrial). The AQI on any given day is usually driven by whichever of these is highest.

Has Baltimore had a major air-quality or smog event?

June 2023 Canadian wildfire smoke briefly pushed Baltimore AQI above 200.

How can I check Baltimore'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.

Related