Source of strange, worrisome odor in SW Washington remains mysterious as rain rolls through area

Authorities are still trying to figure out the cause of the sharp, concerning odor that swept through southwest Washington and into the Portland metro area on Tuesday night and Wednesday morning.

Officials don’t know whether the smell could be dangerous.

“It smells toxic as hell,” one person on Reddit wrote Wednesday morning.

The odor apparently first popped up in Kelso and moved down the I-5 corridor.

The Portland office of the National Weather Service analyzed winds overnight and estimated the route the odor took.

Cowlitz County Fire District 5 reported on Facebook that it had deployed air monitors in Kalama late Tuesday, and they produced “an O2 reading of 20.8, all other substances were at 0, so no gas.”

Local industrial plants and railroads reported no problems or unusual releases, the fire district added.

With raining coming down across the metro area on Wednesday afternoon, the odor appears to be dissipating. Officials continue to investigate.

Cowlitz County Emergency Management advised that anyone smelling the odor should stay indoors and close doors and windows.