Columbus, OH Air Quality Index (AQI) Today

The local baseline here is diesel, spread thin. Columbus is where I-70 crosses I-71, with the I-270 outerbelt closing a ring around both, and Rickenbacker south of downtown puts a dedicated cargo airport and a Norfolk Southern intermodal terminal, opened in 2008, on one site. That freight load is real, but it is distributed across a low-density metro rather than stacked into a single industrial corridor, so no one part of the city carries most of it.

There is little here to hold any of it in place. Central Ohio is glaciated till plain, and the only relief inside the metro is the shallow trench the Scioto and the Olentangy have cut through it. On a calm night that is enough for cool air to settle along the river bottoms and keep the previous evening’s exhaust near the ground until the sun mixes it out after sunrise. It is not enough to stack a load of pollution up over several days.

The contrast with the other end of the state is the useful one. Cleveland concentrates a century of heavy industry in one incised river valley that traps on cold mornings. Columbus has neither the concentration nor the walls, so its worst readings tend to track weather moving across the region rather than any single local source.