The last 18” may have been Oct 11 but even that may have been a tick under. I lived there then and I recall the official measurement being a little suspect. Whatever, it was high impact as we know. I think maybe higher spots in Danbury reached 18-20” in 03/18 but DXR did not. I’m not sure the airport has/had an official obs for snow. Feb13, the noaa map says they’re shy of 20” but I think they came close.