[Ann Archy]

In 1982 this volcano erupted and changed the world’s climate!! iirc.

[tomkat]

1883, and yes, it pretty much cancelled summer in many parts of the world.

[palmer]

El Chichon in 1982. The cooling was offset by the warming from a super El Nino. https://www.wired.com/2012/03/looking-back-at-the-1982-eruption-of-el-chichon-in-mexico/