Binding in the floor shifter

[trainguy]

Chuck L noticed while driving my 39on the Barners Tour in Fl this year that it required more effort to shift the trans.Vic P when he drove the car commented that it required mor effort than his 39,I tried it and agreed.I drove the car today ,back home ,and the effort to shift it seems normal .I am wondering why! The only thing changed is the outside temp.80deg versus 15deg.Any ideas?Phil