Ryan, you must be talking about if you have the OBC. I don't have CODE and I can't personalize the Memo in my '87 that doesn't have an OBC. According to the owner's manual for my car, the Memo function (on a non-OBC car), will emit a beep whenever it is one minute before the hour - so it beeps at 1:59, 12:59, 11:59, etc. The manual says that the purpose of this is so that you can be reminded of a radio show that begins on the hour and give you time to change the radio station.
I noticed the 38 degrees warning for the first time the other day - it caught me by surprise too.