New Orleans, LA Air Quality Index (AQI) Today

There is no terrain here to trap anything, and the wind off the Gulf ventilates the metro more days than not, so New Orleans has bad events rather than a bad season.

The most distinctive of them burns underground. Bayou Sauvage sits inside the city limits, in eastern New Orleans, and when drought pulls the water table down in marsh like it, fire gets into the peat soil and smolders instead of flaming. Smoke off a smoldering marsh is heavy in fine particulate, and rain does not reliably end the fire. It also does something no air quality figure can express. Mixed with the region’s overnight fog it forms superfog, in which visibility can fall to nothing across a few hundred feet of road. In October 2023 that combination caused a 168-vehicle pileup on Interstate 55 in St. John the Baptist Parish that killed eight people and injured sixty-three.

Under the events runs a steady industrial baseline: refineries and chemical plants strung along the Mississippi upriver toward Baton Rouge, and the ship and barge traffic working the port below them. Autumn adds cane-leaf burning on the sugarcane farms outside the metro, which is a rural source with an urban downwind side.