At the south rim the average high is in the upper 50sF and the average low is in the mid 20s. See the link below for a TON of data from last year about that location. I don't think they have reliable weather data like that for the bottom of the canyon, but it will be noticeably warmer at the bottom than at the rim.
Mrs. Lift, also known as Momma, was the main antagonist of Throw Momma from the Train. She was Owen's old mother who mistreated him and his friend Larry. At the end of the film, it was revealed by Owen that she died from natural causes. She was portrayed by Anne Ramsey.
Side one.  1 Love Child (Pam Sawyer, R. Dean Taylor, Frank Wilson, Deke Richards) â 2:58.  2 Keep an Eye (Nickolas Ashford, Valerie Simpson) â 3:08.  3 How Long Has That Evening Train Been Gone (Sawyer, Wilson) â 2:48.  4 Does Your Mama Know About Me (Tom Baird, Tommy Chong) â 2:54.