Big Bird on Mr. Rogers

[Ziffel]

Well Big Bird came on Mr. Rogers' show in June 1981 and I see Mr. Rogers came on SS on show# 1575, which was in 1981. Just have to find out when in 1981 to determine if it was the same week. I see in the Sesame Street episode guide thread that this show also had a heat wave as the running topic, so looks like it was right around June.