"I still haven't quite dealt with it. I'll get stronger as time goes, but we were close, you know," Vedder told Stern on Monday.
Vedder continued to talk about their friendship and how he spent a lot of time with Cornell going hiking, mountain biking and how they would chase a dog in the rain drinking beer.
"I would hang out with him outside of the band more than, you know, even the other band guys and I didn't know that many people in Seattle," he said.
Cornell died by suicide at the age of 52 in May 2017.
"We just hung out for a couple of days and he just asked me a few questions. I told him things, like make sure your guitar covers your balls at all times," Vedder said, noting that sometimes a guitar is held too high where it looks like a bib.